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Disposal practices for unused medications around the world
Environment International 37 (2011) 292–298
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Environment International j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / e n v i n t
Review
Disposal practices for unused medications around the world Alfred Y.C. Tong a,⁎, Barrie M. Peake b,1, Rhiannon Braund c,2 a b c
School of Pharmacy and Chemistry Department, University of Otago, PO Box 56, Dunedin 9054, New Zealand Chemistry Department, University of Otago, PO Box 56 Dunedin 9054, New Zealand School of Pharmacy, University of Otago, PO Box 56, Dunedin 9054, New Zealand
a r t i c l e
i n f o
Article history: Received 18 July 2010 Accepted 2 October 2010 Keywords: Medicines disposal Unused medicines Medicines wastage Medication disposal
a b s t r a c t Pharmaceuticals have been detected throughout the environment where at least in some cases, they have been shown to have a detrimental effect. Many result from improper patient disposal of unused pharmaceuticals via environmentally-unfriendly routes, such as the sink, toilet or rubbish bin. This review surveys the current peerreviewed literature on attitudes and practices to medicine disposal methods as reported by patients and the various medication disposal and destruction systems around the world. A literature search was carried out using the keywords 'medicines disposal', 'unused medicines', 'medicines wastage', and 'medication disposal' in the PubMed TM, ISI Web of Knowledge TM, Google Scholar TM, Medline TM, Scopus TM and International Pharmaceuticals Abstracts TM up to the end of May 2010. Twelve peer-reviewed articles with specified sample sizes were selected. The most popular methods for medication disposal were in the garbage, toilet or sink. Liquid medications were more likely to be rinsed down the sink, as opposed to solid tablets and capsules which were more likely deposited in the rubbish bin. Much confusion exists about the 'proper' way of medication disposal as many countries do not have standard medication disposal protocols. Furthermore, some pharmacies around the world refused to accept unused medications or discouraged the practice. Patients with knowledge about the impact of pharmaceuticals in the environment were more likely to return medications for proper disposal and destruction. It is concluded that it is of paramount importance that a formalized protocol for patient disposal and destruction of pharmaceuticals be implemented around the world. © 2010 Elsevier Ltd. All rights reserved.
Contents 1. 2. 3. 4.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Search strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1. Methods of medication disposal . . . . . . . . . . . . . . . . . . . 4.2. Influence of environmental awareness on medication disposal methods . 4.3. The availability of formalized protocols for medicines disposal . . . . . 5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction There have been many recent reports of pharmaceutical compounds and their metabolites in the environment (Kasprzyk-Hordern
⁎ Corresponding author. Tel.: +64 3 479 5285. E-mail addresses: [email protected] (A.Y.C. Tong), [email protected] (B.M. Peake), [email protected] (R. Braund). 1 Tel.: + 64 3 479 7927. 2 Tel.: + 64 3 479 7240. 0160-4120/$ – see front matter © 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.envint.2010.10.002
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et al., 2008; Snyder, 2008; Kummerer, 2009; Snyder and Benotti, 2010). Pharmaceutical compounds have been detected in surface (Bartlett-Hunt et al., 2009) and drinking (Benotti et al., 2009) water, and even though the concentrations detected are of the order of nanograms to micrograms per liter (Moldovan et al., 2007) there remains an uncertainty about whether compounds at these levels pose a chronic threat to human or animal health (Zuccato et al., 2006). Much research has also been undertaken on the levels of pharmaceuticals in waste water and their possible environmental consequences (Pomati et al., 2006; Lienert et al., 2007; Schmitt-Jansen et al.,
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2007; Li and Randak, 2009; Parolini et al., 2009; Rosal et al., 2010). However much less is known about the factors that lead to the occurrence of these pharmaceuticals in all these different parts of the environment. Clearly a major factor is the human excretion of these pharmaceuticals and their metabolites into sewage (Heberer et al., 2002) but another significant factor is the human disposal of unwanted medication. Pharmaceuticals may enter the environment through improper disposal of unused and expired pharmaceutical dosage forms in the toilet or sink (Ruhoy and Daughton, 2007; Comeau et al., 2008). Processes employed in sewage treatment plants are often ineffective in removing all improperly disposed pharmaceuticals and therapeutic medication excreted in unchanged or metabolized forms from effluent before discharge into waterways (Nakada et al., 2006; Kim and Aga, 2007; Zorita et al., 2009) and thus pharmaceuticals can potentially be discharged into waterways. If unwanted pharmaceuticals are disposed of in the garbage, they eventually end up in landfills with the potential to be discharged into the environment as leachate (Barnes et al., 2004). The use of pharmaceuticals is on the rise, with an estimated increase from 2 billion to 3.9 billion prescription numbers yearly between 1999 and 2009 in the US alone (Kaiser Family Foundation, 2010). Unused and expired medicines often are the result of patients' poor compliance to certain medicines (Lindberg et al., 2008) resulting in many cases is in not taking or finishing courses as directed by the prescriber (Thormodsen et al., 1997; Aziz and Ibrahim, 1999; Ruhoy and Daughton, 2008). Excessive prescribing by doctors (Ekedahl, 2006) may also increase the volume of unused medication. If the likely environmental impact of pharmaceuticals is to be reduced then we must address the issues related to improper disposal practices. Some of the questions pertaining to the disposal of unused pharmaceuticals by households and individuals include: what are the current methods employed by individuals to dispose of unused and expired pharmaceuticals? Is their choice of disposal methods influenced by any prior knowledge of environmental issues associated with pharmaceuticals? Most importantly, is there a need for a formalized protocol for disposal and destruction of unused and expired medications worldwide in order to minimize their potential impact on the global environment? In order to evaluate current and past medicine disposal methods by the public around the world, and the impact such methods may have on the environment, it is necessary to establish what are the reported practices and attitudes to medicines disposal. By obtaining this information from the peer-reviewed literature studies, it is possible to infer whether such disposal practices are affected by peoples' demographics and their knowledge of environmental issues concerning pharmaceuticals in the natural environment. This review will also include data on the availability of formalized disposal systems as reported in various countries around the world and deduce their impact on peoples' medication disposal habits. 2. Search strategy The keywords ‘medicines disposal’, ‘ unused medicines’, ‘medicines wastage’, and ‘medication disposal’ were used in searches involving the PubMed TM, ISI Web of Knowledge TM, Google Scholar TM, Medline TM, Scopus TM and International Pharmaceuticals Abstracts TM databases to retrieve references published up to the end of May 2010. The bibliographies of retrieved references were also searched. Only peer-reviewed literature were considered but not restricted to just being written in English. Studies involving both random and convenience samplings were included as well as studies employing various types of survey instruments (such as telephone questioning, interview with participants and mailed questionnaire). Data obtained from the studies included the study population demographics of the participants, the methods for disposal of unused
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and expired medication, and participants' attitudes to the disposal of medications when stated. The studies that were included contained information regarding the sample size of participants. Information was also noted regarding participants' awareness of environmental issues surrounding pharmaceuticals in the environment, and whether participants felt a proper disposal system for unused and expired pharmaceuticals were necessary in their country (or if one was already established, whether they were inclined to use it). 3. Methodology Fourteen studies were identified in the primary peer-reviewed literature. One study did not state a sample size for the participants who responded and so was excluded from the review. The methodologies used and the target populations investigated in the remaining 13 peer-reviewed studies are summarized in Table 1. The range of methods used to deliver the questionnaire to participants included: postal surveys (3), self-administered questionnaires (2), telephone surveys (4), online or computerized surveys (3) and interviews (2). One study employed both interview and telephone survey techniques (Blom et al., 1996). Only five studies (Ridout et al., 1986; Sullivan and George, 1996; Gotz and Keil, 2007; Kotchen et al., 2009; Persson et al., 2009) involved randomized selection of participants via various methods such as the use of an electoral register (Ridout et al., 1986; Sullivan and George, 1996) or through the telephone directory (Kotchen et al., 2009). The demographics of participants varied between studies. Although most studies had a majority of female participants, 66% of the participants involved in the Kuwait study (Abahussain et al., 2006) were males. The age profile of the participants also varied in all the studies and it was not possible to generalize the demographics as such data was missing from some studies. One study limited their study population to middle and upper class households (Abahussain and Ball, 2007) and another surveyed participants from town, suburb and rural settlements (Krupiene and Dvarioniene, 2007). Yet another study only considered responses from participants if they were actively involved in the disposal of household medication (Gotz and Keil, 2007). The educational status of participants was varied, but 62% of the participants in the Kuwait study (Abahussain and Ball, 2007) had a university education, compared to the early Southampton studies in England (Sullivan and George, 1996; Ridout et al., 1986) where most of the participants were skilled manual workers. 4. Results and discussion 4.1. Methods of medication disposal The methods used by respondents to dispose of their unused medication and their extent of usage are summarized in Table 2. The most common method for disposal of pharmaceuticals by individuals or households is disposal in the garbage and is by far the predominant method of disposal reported in Kuwait (Abahussain et al., 2006; Abahussain and Ball, 2007), United Kingdom (Bound and Voulvoulis, 2005), and Lithuania (Krupiene and Dvarioniene, 2007), particularly in towns and suburban areas; however storage of unused medications (55%) and return of medications to pharmacies (45%) were the predominant ‘disposal’ methods in a Swedish survey in 2007 (Persson et al., 2009). Home backyard burning of expired and unused medication was also a common means of disposal in Lithuania with this method being utilized by 50% of the respondents living in the countryside (Krupiene and Dvarioniene, 2007). It is also interesting to note that no one surveyed in the Lithuanian countryside utilized the sewage system as a means for disposal of unwanted medications (due to the unavailability of working sewage systems in many parts of the country). Similarly, no one reported on the use of the toilet or sink as a
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Table 1 Studies and their methodologies found in the peer-reviewed literature. Year of Author(s) study
Locality
Research instrument
Sampling method and population investigated
1986
Ridout et al.
England (Southampton)
Postal questionnaire with follow-up A 1:200 random sampling drawn of non-responders after 1 month. from the electoral register.
1996
Blom et al.
Netherlands
1996
Kuspis and Krenzelok
United States
1996
Sullivan and George
England (Southampton)
Samples drawn from communities Interviews and phone surveys (latter 10% of samples) by the Dutch with a population N 100,000 inhabitants; one address was used Institute of Public Opinion, 1994. as the starting point for another five addresses. Callers and pharmacists were asked Callers to a poisons information the question “What do you do with centre. 100 rural and urban pharmacists. your expired medications”. Postal questionnaire with follow-up A 1:200 random sampling drawn of non-responders after 1 month. from the electoral register.
2005
Bound and Voulvoulis
England (cities/towns in Southeastern UK)
2006
Abahussain et al.
Kuwait
2006
Seehusen and Edwards
United States (Madigan, Tacoma, Washington State)
2007
Abahussain and Ball
Kuwait
2007
Gotz and Keil
Germany
2007
Krupiene and Dvarioniene
Lithuania
2009
Braund et al.
New Zealand
2009
Kotchen et al.
United States (Ventura and Santa Barbara Counties, California)
2009
Persson et al.
Sweden
Close-ended questions: interview. Asked about disposal methods and types of medications disposed. Self-administered questionnaire on disposal methods and types of medications disposed. Anonymous survey on computerized kiosks.
Self-administered questionnaire that asked participant opinion on household medication disposal and views on a proper disposal. system Bias-controlled ‘interview’ delivered on multimedia pen pads.
Close-ended postal questionnaire, with two open-ended questions regarding whether they returned unused medication to pharmacies. Closed-question online survey instituted by the National Poisons Centre.
Participants 18 years and over. 55% female, most (40%) were skilled manual workers. Most (35%) were 35–49 years in 2–3 (48%) person households.
Varied callers, randomly selected pharmacies (46 hospital-based and 54 private community pharmacies). Participants 16 years and over, most between 30 and 44 years. 53% female, most (37%) skilled manual workers. 54.8% female. The social-economic Interviewees drawn from a representative mix of participants in status and age ranges of the participants varied. cities, towns and villages. Mean age of respondents 37.9 years. Outpatients from hospital pharmacies collecting filled 66% male, 62% had a university prescriptions at five large hospitals. degree. Convenience sample of outpatients 52% of participants were female, in a hospital waiting room. mostly young (18–39 years) and old (N 60 years) (28.9% and 32.9% of the sample respectively). Middle or high social-economics Convenience sample of 250 households. households. Apartments not included. Random selection of participants. Final sample chosen after adjustment for demographic outliers. Convenience sample of participants' towns, suburbs and settlements and the countryside.
German speakers aged 14 years and over responsible for household disposal of pharmaceuticals. 67% female. Participants from variable socialeconomic groups, age, sex, and education.
Convenience sampling from anonymous website visitors Multiple entries from a similar visitor was eliminated by data checks. Telephone survey of randomly selected households; participants chosen by generating random telephone numbers.
Variable social-economic groups, age, sex and education.
Closed questions regarding medicines disposal, awareness of medicines in the environment and willingness to pay for a disposal system. Telephone questionnaire, randomly Closed questions on medicines chosen from Swedish-speaking disposal and whether medicine disposal habits correlated with their residents in Sweden. attitudes.
means for disposal in Sweden (Persson et al., 2009). By contrast, in a 2006 US study (Seehusen and Edwards, 2006) many used the sink or toilet as the method of disposal, or returned their unwanted medications to a healthcare provider or the pharmacy. However, it is important to note that this study was carried out in a US Army Medical Centre and only methods which directly discharge pharmaceuticals into the aquatic environment (via the sewage system) were surveyed; thus it was unknown how many participants would have disposed of their medications in the rubbish. The method of disposal of medication was also influenced by the dosage form of the medication. Indeed a disposal study in New Zealand (Braund et al., 2009) reported that the majority of participants in an online questionnaire involving medicines disposal, used the sink or toilet as the preferred method for disposal of liquid dosage forms such as suspensions (55% of the survey sample) whereas the rubbish bin was the preferred method for disposal of tablets/ capsules (51%) and semi-solid dosage forms such as ointments and
Demographics of respondents
Person answering telephone was chosen if 18 years or over. Gender was evenly split; 42.6% had a university degree. Mean age 49.5 years. Participant was person who answered the phone provided he/she was 15 years or older.
creams (80%). In contrast, less than 1% of the respondents reported disposal of ointments and creams into the sewage, only 19% reported to have disposed of tablets and capsules in the sink or toilet and only 24% of the respondents disposed of liquid formulations in the garbage. Furthermore, the German study (Gotz and Keil, 2007) reported that 32% of the participants disposed of their unused liquid formulations ‘always’, ‘usually’ or ‘sometimes’ in the toilet or sink, whilst only 10% of solid dosage forms were disposed of in the toilet or sink. Moreover, the type of medication may also influence consumer disposal according to a nationwide Dutch survey in the 1990s (Blom et al., 1996). One of the questions asked of the participants during the survey interview was “How do you dispose of particular classes of medication, such as cough medicine, painkillers, and skin ointment of antibiotics?” Whilst 52% and 42% of the participants said antibiotics and painkillers should be returned to the pharmacy respectively, 27% would dispose cough medications in the garbage or toilet and 26% in the sewage system. Only 27% of participants would return cough
Table 2 Methods used to dispose of unused medication as reported by the peer-reviewed literature. Method of disposal Locality (with Toilet or sink formulations or setting)
Garbage
Other (stated)
Return to pharmacy
Sample size (n)
1986 Ridout et al. 1996 Blom et al.
United Kingdom Netherlands
46% 3%
14% 9%
17% 58%
443 2154
1996 Kuspis and Krenzelok
United States
35.4%
54%
1.4%
500
1996 Sullivan and George 2005 Bound and Voulvoulis
United Kingdom United Kingdom
27% 11.5%
15% 63.2%
34% 21.8%
400 392
2006 Abahussain et al. 2006 Seehusen and Edwards 2007 Abahussain et al. 2007 Gotz and Keil
11.2% 53.8% (toilet) 35.2% (sink) 2.0% 1% (always), 2% (usually), 7% (sometimes) and 6% (rarely) 10% (always), 8% (usually), 13% (sometimes) and 12% (rarely) 8% 6% – 55%
76.5% – 97% 7%a (always), 9%a(usually), 14%a (sometimes) and 13%a (rarely)
11.9% 300 22.9% 301 – 200 29%a(always) 11%a(usually) and 1306 15% a(sometimes) 11%a(rarely)
89% 87% 50% 24%
2% (burning unused medications) 12.5% (burning unused medications) 50% (burning unused medications) 0.7% (give away or burn)
3% – – 17%
200b
19%
51%
2.4% (give away or burn)
24%
452
b1%
80%
2.4% (give away or burn)
13%
452
2009 Kotchen et al.
Kuwait United States Kuwait Germany (solid medications) Germany (liquid medications) Lithuania (towns) Lithuania (towns) Lithuania (countryside) New Zealand (liquid medicines) New Zealand (tablets and capsules) New Zealand (ointments and creams) United States
15% (kept medicines) 16% (chemical waste) and 6% (kept medicines) 7.2 (kept medicines) and 2% (finished medications) 15% (kept medicines) 3.5% (waste sites or other disposal facility) 8.5% (give to friend) 14% (returned to healthcare provider) 0.5% (give to friend) 23% a (recycled alongside cardboard and plastics) and 15%a(toxic waste bins)
28%
45%
6%
1005
2009 Persson et al.
Sweden (2001 survey)
–
7%
41%
1000
2009 Persson et al. 2009 Persson et al.
Sweden (2004 survey) Sweden (2007 survey)
– –
3% 3%
5% (hazardous waste centre), 12% (store at home) and 4% (unspecified method) 48% (kept medicines) 2% (recycling station) 1% (health centre) 54% (kept medicines) 55% (kept medicines)
42% 43%
1000 1000
2007 Gotz and Keil 2007 Krupiene and Dvarioniene 2007 Krupiene and Dvarioniene 2007 Krupiene and Dvarioniene 2009 Braund et al. 2009 Braund et al. 2009 Braund et al.
a b
452
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Year of study and author(s)
No differentiation between dosage forms in disposal routes other than toilet/sink. Total number of participants from towns, suburbs/settlements and countryside.
295
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medications to the pharmacy. Therefore, it is likely people return unused medications considered to be more harmful to pharmacies. 4.2. Influence of environmental awareness on medication disposal methods The association between environmental pollution and improper medicines disposal is seemingly a recent concept even to health professionals. In the 1990s, it was acceptable for pharmacists in the United States to advise patients to dispose of unused medications in the their own sink, toilet or garbage if they did not or could not return their medications to the pharmacy (Kuspis and Krenzelok, 1996). It has been reported as recently as 2006 that 35% and 21% of the participants in a US study (Seehusen and Edwards, 2006), thought that it was appropriate to flush medications down the sink or toilet respectively. Some studies reported in the literature have also asked whether participants knew of the environmental risks associated with improper disposal of medication. In a Swedish randomized telephone survey (Persson et al., 2009) there was no reported prevalence of any participant flushing unused medication down the toilet or sink in the 2007 survey, and most opted to store their unused medication or return the medications to the pharmacy for disposal. Indeed, participants that returned unused medication to the pharmacy were asked why they did so. In 2007, 42% of the participants said they were worried about environmental pollution by medications compared with only 26% giving the same response in 2001. Even in a Dutch study from the 1990s 72% and 80% of the participants who stated they returned unused medication to a pharmacy or to a chemical waste facility respectively, did so because they were concerned about the environment (Blom et al., 1996), whilst the participants who disposed unused medication predominantly via the sewage or the garbage did so because it was convenient. Furthermore, a recent study in the United States (Kotchen et al., 2009) asked participants whether they were aware that pharmaceuticals have been detected in the environment. Forty-three percent of participants stated they were aware of this fact and these participants were more likely to dispose of medications in a manner that reduces potential environmental pollution (i.e. return unwanted medications to pharmacies). However, improper disposal was still prevalent in environmentally- aware participants in this US study (38.7% in trash; and 23.2% in toilet or sink), which suggests that awareness of environmental issues surrounding medicines disposal only partially accounts for peoples' medicine disposal habits. It is apparent that environmental awareness may not be associated with educational status. In Kuwait (Abahussain and Ball, 2007) 62% of the study sample were university graduates or had some form of tertiary education but 97% of the study participants stated they would dispose of their unwanted medications in the garbage. From this data, medicine disposal habits are clearly influenced by environmental awareness, but this is not the sole factor which will determine how patients discard their unused medications. 4.3. The availability of formalized protocols for medicines disposal The availability of official state guidelines for disposal of unwanted medication is a major influence on how people dispose of unused pharmaceuticals. From the results of two UK studies (Table 2) it can be seen that more people returned unused medication to pharmacies in 1996 compared to 1986 (Ridout et al., 1986; Sullivan and George, 1996). This may be due to proper disposal of medication campaigns promoted by the Royal Pharmaceutical Society of Great Britain in the 1990s which advocated that patients should return any unused, excess and/or expired medications to pharmacies for proper disposal. Conversely, there were no official guidelines for pharmaceutical disposal set by the Food Drug and Administration (FDA), state
pharmacy boards, or the Environmental Protection Agency (EPA) in the US in the 1990s (Kuspis and Krenzelok, 1996) and this situation may have led people in the US to dispose of pharmaceuticals conveniently in the toilet, sink or garbage at that time. No official guidelines for disposal of unwanted medications exist in Kuwait (Abahussain and Ball, 2007) and 54% of the responding participants in an earlier Kuwaiti study (Abahussain et al., 2006) thought it was appropriate that the option of returning medicines in pharmacy dropboxes should be available to the public. Furthermore, many people thought it was appropriate that medicines should be disposed of in secure bins in shopping malls (21%) and home collection schemes (15%). In addition 40% of the responding participants suggested that public knowledge of how unused medications should be disposed of was lacking in Kuwait. However, no medications were collected in 2007 when a pilot collection scheme was trialed with survey participants in Kuwait (Abahussain and Ball, 2007). Nevertheless this latter study surveyed participants from middle to high socialeconomic groups, whereas the previous 2006 study (Abahussain et al., 2006) surveyed hospital patients in a Kuwaiti government hospital who were from lower social-economic groups. It could be that these patients may not have been able to afford expensive methods of medicines disposal and may have been more dependent on the state to deal with waste medicines compared to the situation for middle or upper class participants. However this study was undertaken in a hospital and so there is always the likelihood that patients were providing answers that they thought were ‘correct’ and establishing a proper medicines disposal system and returning medication to pharmacies for disposal are seemingly appropriate answers even to participants unaware of proper disposal methods. In Lithuania most people dispose of unwanted medications in the garbage or burn them (Krupiene and Dvarioniene, 2007). Whilst backyard burning of pharmaceuticals may render pharmaceuticals to be inactive (Peake and Braund, 2009), complete combustion of the pharmaceuticals is never guaranteed, and residues from the incineration site may still be discharged into the environment albeit in partially or fully oxidized forms. This may be a particular consideration for people in the countryside, where the natural environment is in closer proximity to burn sites and hence the products of combustion arising from burning. Pharmacies in Lithuania are poorly utilized as drug collection depots (Krupiene and Dvarioniene, 2007). It was reported that only 3% of the respondents residing in towns returned unwanted medication to pharmacies. Many may have failed to return medications to pharmacies because many felt stigmatized or stupid when seen carrying medications back into the pharmacy. As many as 73% of the study sample did not think pharmacies were able to take back unwanted medication. In addition, many pharmacies may have actively refused to accept returned medications and thus added confusion to the ‘proper’ method for disposal of unwanted medications. Some state laws in the United States actually prevent pharmacies from accepting unwanted medications (Seehusen and Edwards, 2006) particularly controlled substances as these medications may be diverted (Vivian, 2009). Controlled medications are a major hurdle in the US for the establishment of a convenient, cost-effective nationwide disposal protocol — such substances have to be inventoried by law enforcement even in many small pilot collection programs me in the US (Glassmeyer et al., 2009) and this adds extra running costs to the system. The current FDA recommendations, in fact, list 26 ‘dangerous’ medications which should be flushed down the toilet (Mitka, 2009). For all other medications the FDA has recommended that, if a ‘take-back’ or ‘mail-back’ program is unavailable then unused solid medications should be crushed with an unpalatable substance, such as cat litter, mixed, and disposed in the garbage in a leakproof, sealed container (Glassmeyer et al., 2009). Whilst such practices may reduce the likelihood of poisonings and diversion (Inciardi et al., 2009), the long term consequences associated with the exposure of the environment to such pharmaceuticals from the sewage or landfill is at
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present unknown. Furthermore it has been reported that the White House and FDA have offered conflicting information on medication disposal which may have added to confusion (Erickson, 2010). People who visit pharmacies and healthcare centers on a regular basis may be more educated about returning medication to pharmacies; the lack of pharmacy access to countryside dwellers in Lithuania may also be another reason why these people living in this country did not return medication to pharmacies. In the United States, it was shown that patients who were counseled to properly return unused medications to pharmacies and healthcare providers were more likely to do so (Seehusen and Edwards, 2006). The need for public education on disposal of pharmaceuticals is further emphasized by a recent New Zealand study (Braund et al., 2009) where nearly one-quarter of the participants surveyed stated they kept unwanted medicines around the household because they did not know what to do with them. Germany is another country that is reported as having no state-run disposal system, and guidelines for disposal of dosage forms are different between regions (Gotz and Keil, 2007). Some prescribed medicines have disposal instructions on the packaging; however, this does not apply to all pharmaceuticals in Germany. It has been recommended that standardized and legally binding protocols for drug disposal are set up in this country but many of the participants stated that they were unwilling to pay for the institution of an official medications disposal system. All solid wastes in garbage are subjected to high temperature incineration in Germany and thus the likelihood for medicinally rich leachate to be discharged from a landfill is unlikely. Subsequently much environmental pollution will result entirely from the medicines that are disposed of in the sewage system in Germany. At least 55% of the participants remarked that they sometimes returned their unused medication to pharmacies, suggesting that many people may know that it is appropriate to return unused medications to pharmacies but instead they found it more convenient to continue to dispose of pharmaceuticals at home. Indeed, it has been reported that laziness may also be a contributing factor for a lack of medication returns to pharmacies in Sweden (Persson et al., 2009). However, it was not possible to ascertain the type and quantity of medications that were disposed of in the German study; or the actual frequency of disposal via the various methods reported by the participants, as this would have required a knowledge of whether patients are taking their medications and such compliance data were not recorded in this study. Ultimately, the cost of setting up a nationwide medicines disposal system accessible by the public may be substantial, but the low prevalence of improper disposal methods as reported in Sweden (Persson et al., 2009) is clearly influenced not only by the people's attitudes and knowledge of medicine disposal practices, but also the availability of a well-run disposal system. Since 1971 Sweden has an established reverse distribution system run by a major pharmacy wholesaler in conjunction with the state pharmaceutical association. Medicines returned to pharmacies are ultimately destined for incineration at high temperatures, and the residual deposited in specified landfills. It has been estimated that 73% of Swedish people eventually return unused medications to pharmacies. It can be said that in order for a ‘disposal and destruction’ system to be successful, it has to be used by the public. The effectiveness of the Swedish disposal system may, of course, only apply to Sweden; this could be the fact that Swedish people appear to be very compliant with state protocols, but if the same system was transferred to another country, different social attitudes to state protocols may render the system ineffective.
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unused medication and how improper disposal methods may affect the environment. The most popular medicine disposal methods observed in many of the studies still have the potential to detrimentally pollute the environment. Confusion exists in different countries as many countries lack adequate guidelines for the ‘proper’ disposal of unused medications. Public services around the world, including government and health sectors, need to be more proactive about educating patients on how to use and dispose of medication in a more environmentally acceptable manner, and establish an official guideline that is relevant to their particular country. For certain parts of the world, proper disposal of unused medications may include schemes that allow patients to conveniently and discreetly return unused medication to a pharmacy, rather than discourage and embarrass patients for doing so. This may be particularly important in countries which offer free or subsidized medications and thus, there is an increased risk of accumulation and hoarding of unused medication. The establishment of formalized state-run collection and disposal systems that are cost-effective, easily accessible to the public and actually employing methods which completely degrade unwanted pharmaceuticals is of paramount importance as this avoids confusion about the ‘correct’ way to dispose of medications. A typical collection and disposal system may be set up to 1) collect unwanted medicines that have been returned to pharmacies or 2) collect the medicines directly from patients, depending on cost constraints and the willingness of patients to use the suggested system. To minimize discharge into the environment, the pharmaceuticals can then be completely destroyed by high-temperature incineration, and the ashes deposited in leakproof containers bound for specialized landfills dealing in pharmaceutical waste. Of course, it would be mandatory that consumers are willing to pay for the institution and running costs of such a system. Future directions for research in this area may include further evaluation of user-friendly and cost-effective means of returning unused medications to pharmacies, and the most effective and safe means for their ultimate disposal. Of course, one other alternative solution which has not been reviewed at all in this paper is for physicians to minimize their prescribing of excessive and unnecessary medication; such a practice would drastically reduce the medicines needing to be disposed of in used or unused forms and hence their potential environmental impact. In turn, pharmacists also have a role to play in ensuring that patients take all of their prescribed medications. Finally, it is clear from this review that the few studies that have been undertaken on disposal practices have involved only a small number of countries. For a more comprehensive and accurate picture of the global situation, further research needs to be undertaken in other countries, particularly those with large human populations and hence where pharmaceutical disposal practices may have a significant impact on the global environment. In addition, there has been little analysis of pharmacists' attitudes and methods for disposal of unused medication from pharmacies, which is another area that requires further investigation. Finally, as this review has shown, how people dispose of pharmaceuticals may depend on cultural and social differences, and this opens avenues for future studies on how these factors may impact on medication disposal habits. Overall, the limited collated evidence suggests there is a pressing need for increasing public awareness on the issue of medication disposal, and currently, patients, scientists, health professionals and government officials are all only starting to become aware of the various methods employed for unused medication disposal, and how these may impact on the environment.
5. Conclusion Acknowledgements The current evidence collated from a relatively small number of studies undertaken in different countries suggests that patients still very much lack the knowledge as to the proper disposal of their
Dr. Eike Breitbarth (Chemistry Department, University of Otago) for assistance in translating some of the literature written in German,
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Contents lists available at ScienceDirect
Environment International j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / e n v i n t
Review
Disposal practices for unused medications around the world Alfred Y.C. Tong a,⁎, Barrie M. Peake b,1, Rhiannon Braund c,2 a b c
School of Pharmacy and Chemistry Department, University of Otago, PO Box 56, Dunedin 9054, New Zealand Chemistry Department, University of Otago, PO Box 56 Dunedin 9054, New Zealand School of Pharmacy, University of Otago, PO Box 56, Dunedin 9054, New Zealand
a r t i c l e
i n f o
Article history: Received 18 July 2010 Accepted 2 October 2010 Keywords: Medicines disposal Unused medicines Medicines wastage Medication disposal
a b s t r a c t Pharmaceuticals have been detected throughout the environment where at least in some cases, they have been shown to have a detrimental effect. Many result from improper patient disposal of unused pharmaceuticals via environmentally-unfriendly routes, such as the sink, toilet or rubbish bin. This review surveys the current peerreviewed literature on attitudes and practices to medicine disposal methods as reported by patients and the various medication disposal and destruction systems around the world. A literature search was carried out using the keywords 'medicines disposal', 'unused medicines', 'medicines wastage', and 'medication disposal' in the PubMed TM, ISI Web of Knowledge TM, Google Scholar TM, Medline TM, Scopus TM and International Pharmaceuticals Abstracts TM up to the end of May 2010. Twelve peer-reviewed articles with specified sample sizes were selected. The most popular methods for medication disposal were in the garbage, toilet or sink. Liquid medications were more likely to be rinsed down the sink, as opposed to solid tablets and capsules which were more likely deposited in the rubbish bin. Much confusion exists about the 'proper' way of medication disposal as many countries do not have standard medication disposal protocols. Furthermore, some pharmacies around the world refused to accept unused medications or discouraged the practice. Patients with knowledge about the impact of pharmaceuticals in the environment were more likely to return medications for proper disposal and destruction. It is concluded that it is of paramount importance that a formalized protocol for patient disposal and destruction of pharmaceuticals be implemented around the world. © 2010 Elsevier Ltd. All rights reserved.
Contents 1. 2. 3. 4.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Search strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Results and discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1. Methods of medication disposal . . . . . . . . . . . . . . . . . . . 4.2. Influence of environmental awareness on medication disposal methods . 4.3. The availability of formalized protocols for medicines disposal . . . . . 5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction There have been many recent reports of pharmaceutical compounds and their metabolites in the environment (Kasprzyk-Hordern
⁎ Corresponding author. Tel.: +64 3 479 5285. E-mail addresses: [email protected] (A.Y.C. Tong), [email protected] (B.M. Peake), [email protected] (R. Braund). 1 Tel.: + 64 3 479 7927. 2 Tel.: + 64 3 479 7240. 0160-4120/$ – see front matter © 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.envint.2010.10.002
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et al., 2008; Snyder, 2008; Kummerer, 2009; Snyder and Benotti, 2010). Pharmaceutical compounds have been detected in surface (Bartlett-Hunt et al., 2009) and drinking (Benotti et al., 2009) water, and even though the concentrations detected are of the order of nanograms to micrograms per liter (Moldovan et al., 2007) there remains an uncertainty about whether compounds at these levels pose a chronic threat to human or animal health (Zuccato et al., 2006). Much research has also been undertaken on the levels of pharmaceuticals in waste water and their possible environmental consequences (Pomati et al., 2006; Lienert et al., 2007; Schmitt-Jansen et al.,
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2007; Li and Randak, 2009; Parolini et al., 2009; Rosal et al., 2010). However much less is known about the factors that lead to the occurrence of these pharmaceuticals in all these different parts of the environment. Clearly a major factor is the human excretion of these pharmaceuticals and their metabolites into sewage (Heberer et al., 2002) but another significant factor is the human disposal of unwanted medication. Pharmaceuticals may enter the environment through improper disposal of unused and expired pharmaceutical dosage forms in the toilet or sink (Ruhoy and Daughton, 2007; Comeau et al., 2008). Processes employed in sewage treatment plants are often ineffective in removing all improperly disposed pharmaceuticals and therapeutic medication excreted in unchanged or metabolized forms from effluent before discharge into waterways (Nakada et al., 2006; Kim and Aga, 2007; Zorita et al., 2009) and thus pharmaceuticals can potentially be discharged into waterways. If unwanted pharmaceuticals are disposed of in the garbage, they eventually end up in landfills with the potential to be discharged into the environment as leachate (Barnes et al., 2004). The use of pharmaceuticals is on the rise, with an estimated increase from 2 billion to 3.9 billion prescription numbers yearly between 1999 and 2009 in the US alone (Kaiser Family Foundation, 2010). Unused and expired medicines often are the result of patients' poor compliance to certain medicines (Lindberg et al., 2008) resulting in many cases is in not taking or finishing courses as directed by the prescriber (Thormodsen et al., 1997; Aziz and Ibrahim, 1999; Ruhoy and Daughton, 2008). Excessive prescribing by doctors (Ekedahl, 2006) may also increase the volume of unused medication. If the likely environmental impact of pharmaceuticals is to be reduced then we must address the issues related to improper disposal practices. Some of the questions pertaining to the disposal of unused pharmaceuticals by households and individuals include: what are the current methods employed by individuals to dispose of unused and expired pharmaceuticals? Is their choice of disposal methods influenced by any prior knowledge of environmental issues associated with pharmaceuticals? Most importantly, is there a need for a formalized protocol for disposal and destruction of unused and expired medications worldwide in order to minimize their potential impact on the global environment? In order to evaluate current and past medicine disposal methods by the public around the world, and the impact such methods may have on the environment, it is necessary to establish what are the reported practices and attitudes to medicines disposal. By obtaining this information from the peer-reviewed literature studies, it is possible to infer whether such disposal practices are affected by peoples' demographics and their knowledge of environmental issues concerning pharmaceuticals in the natural environment. This review will also include data on the availability of formalized disposal systems as reported in various countries around the world and deduce their impact on peoples' medication disposal habits. 2. Search strategy The keywords ‘medicines disposal’, ‘ unused medicines’, ‘medicines wastage’, and ‘medication disposal’ were used in searches involving the PubMed TM, ISI Web of Knowledge TM, Google Scholar TM, Medline TM, Scopus TM and International Pharmaceuticals Abstracts TM databases to retrieve references published up to the end of May 2010. The bibliographies of retrieved references were also searched. Only peer-reviewed literature were considered but not restricted to just being written in English. Studies involving both random and convenience samplings were included as well as studies employing various types of survey instruments (such as telephone questioning, interview with participants and mailed questionnaire). Data obtained from the studies included the study population demographics of the participants, the methods for disposal of unused
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and expired medication, and participants' attitudes to the disposal of medications when stated. The studies that were included contained information regarding the sample size of participants. Information was also noted regarding participants' awareness of environmental issues surrounding pharmaceuticals in the environment, and whether participants felt a proper disposal system for unused and expired pharmaceuticals were necessary in their country (or if one was already established, whether they were inclined to use it). 3. Methodology Fourteen studies were identified in the primary peer-reviewed literature. One study did not state a sample size for the participants who responded and so was excluded from the review. The methodologies used and the target populations investigated in the remaining 13 peer-reviewed studies are summarized in Table 1. The range of methods used to deliver the questionnaire to participants included: postal surveys (3), self-administered questionnaires (2), telephone surveys (4), online or computerized surveys (3) and interviews (2). One study employed both interview and telephone survey techniques (Blom et al., 1996). Only five studies (Ridout et al., 1986; Sullivan and George, 1996; Gotz and Keil, 2007; Kotchen et al., 2009; Persson et al., 2009) involved randomized selection of participants via various methods such as the use of an electoral register (Ridout et al., 1986; Sullivan and George, 1996) or through the telephone directory (Kotchen et al., 2009). The demographics of participants varied between studies. Although most studies had a majority of female participants, 66% of the participants involved in the Kuwait study (Abahussain et al., 2006) were males. The age profile of the participants also varied in all the studies and it was not possible to generalize the demographics as such data was missing from some studies. One study limited their study population to middle and upper class households (Abahussain and Ball, 2007) and another surveyed participants from town, suburb and rural settlements (Krupiene and Dvarioniene, 2007). Yet another study only considered responses from participants if they were actively involved in the disposal of household medication (Gotz and Keil, 2007). The educational status of participants was varied, but 62% of the participants in the Kuwait study (Abahussain and Ball, 2007) had a university education, compared to the early Southampton studies in England (Sullivan and George, 1996; Ridout et al., 1986) where most of the participants were skilled manual workers. 4. Results and discussion 4.1. Methods of medication disposal The methods used by respondents to dispose of their unused medication and their extent of usage are summarized in Table 2. The most common method for disposal of pharmaceuticals by individuals or households is disposal in the garbage and is by far the predominant method of disposal reported in Kuwait (Abahussain et al., 2006; Abahussain and Ball, 2007), United Kingdom (Bound and Voulvoulis, 2005), and Lithuania (Krupiene and Dvarioniene, 2007), particularly in towns and suburban areas; however storage of unused medications (55%) and return of medications to pharmacies (45%) were the predominant ‘disposal’ methods in a Swedish survey in 2007 (Persson et al., 2009). Home backyard burning of expired and unused medication was also a common means of disposal in Lithuania with this method being utilized by 50% of the respondents living in the countryside (Krupiene and Dvarioniene, 2007). It is also interesting to note that no one surveyed in the Lithuanian countryside utilized the sewage system as a means for disposal of unwanted medications (due to the unavailability of working sewage systems in many parts of the country). Similarly, no one reported on the use of the toilet or sink as a
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Table 1 Studies and their methodologies found in the peer-reviewed literature. Year of Author(s) study
Locality
Research instrument
Sampling method and population investigated
1986
Ridout et al.
England (Southampton)
Postal questionnaire with follow-up A 1:200 random sampling drawn of non-responders after 1 month. from the electoral register.
1996
Blom et al.
Netherlands
1996
Kuspis and Krenzelok
United States
1996
Sullivan and George
England (Southampton)
Samples drawn from communities Interviews and phone surveys (latter 10% of samples) by the Dutch with a population N 100,000 inhabitants; one address was used Institute of Public Opinion, 1994. as the starting point for another five addresses. Callers and pharmacists were asked Callers to a poisons information the question “What do you do with centre. 100 rural and urban pharmacists. your expired medications”. Postal questionnaire with follow-up A 1:200 random sampling drawn of non-responders after 1 month. from the electoral register.
2005
Bound and Voulvoulis
England (cities/towns in Southeastern UK)
2006
Abahussain et al.
Kuwait
2006
Seehusen and Edwards
United States (Madigan, Tacoma, Washington State)
2007
Abahussain and Ball
Kuwait
2007
Gotz and Keil
Germany
2007
Krupiene and Dvarioniene
Lithuania
2009
Braund et al.
New Zealand
2009
Kotchen et al.
United States (Ventura and Santa Barbara Counties, California)
2009
Persson et al.
Sweden
Close-ended questions: interview. Asked about disposal methods and types of medications disposed. Self-administered questionnaire on disposal methods and types of medications disposed. Anonymous survey on computerized kiosks.
Self-administered questionnaire that asked participant opinion on household medication disposal and views on a proper disposal. system Bias-controlled ‘interview’ delivered on multimedia pen pads.
Close-ended postal questionnaire, with two open-ended questions regarding whether they returned unused medication to pharmacies. Closed-question online survey instituted by the National Poisons Centre.
Participants 18 years and over. 55% female, most (40%) were skilled manual workers. Most (35%) were 35–49 years in 2–3 (48%) person households.
Varied callers, randomly selected pharmacies (46 hospital-based and 54 private community pharmacies). Participants 16 years and over, most between 30 and 44 years. 53% female, most (37%) skilled manual workers. 54.8% female. The social-economic Interviewees drawn from a representative mix of participants in status and age ranges of the participants varied. cities, towns and villages. Mean age of respondents 37.9 years. Outpatients from hospital pharmacies collecting filled 66% male, 62% had a university prescriptions at five large hospitals. degree. Convenience sample of outpatients 52% of participants were female, in a hospital waiting room. mostly young (18–39 years) and old (N 60 years) (28.9% and 32.9% of the sample respectively). Middle or high social-economics Convenience sample of 250 households. households. Apartments not included. Random selection of participants. Final sample chosen after adjustment for demographic outliers. Convenience sample of participants' towns, suburbs and settlements and the countryside.
German speakers aged 14 years and over responsible for household disposal of pharmaceuticals. 67% female. Participants from variable socialeconomic groups, age, sex, and education.
Convenience sampling from anonymous website visitors Multiple entries from a similar visitor was eliminated by data checks. Telephone survey of randomly selected households; participants chosen by generating random telephone numbers.
Variable social-economic groups, age, sex and education.
Closed questions regarding medicines disposal, awareness of medicines in the environment and willingness to pay for a disposal system. Telephone questionnaire, randomly Closed questions on medicines chosen from Swedish-speaking disposal and whether medicine disposal habits correlated with their residents in Sweden. attitudes.
means for disposal in Sweden (Persson et al., 2009). By contrast, in a 2006 US study (Seehusen and Edwards, 2006) many used the sink or toilet as the method of disposal, or returned their unwanted medications to a healthcare provider or the pharmacy. However, it is important to note that this study was carried out in a US Army Medical Centre and only methods which directly discharge pharmaceuticals into the aquatic environment (via the sewage system) were surveyed; thus it was unknown how many participants would have disposed of their medications in the rubbish. The method of disposal of medication was also influenced by the dosage form of the medication. Indeed a disposal study in New Zealand (Braund et al., 2009) reported that the majority of participants in an online questionnaire involving medicines disposal, used the sink or toilet as the preferred method for disposal of liquid dosage forms such as suspensions (55% of the survey sample) whereas the rubbish bin was the preferred method for disposal of tablets/ capsules (51%) and semi-solid dosage forms such as ointments and
Demographics of respondents
Person answering telephone was chosen if 18 years or over. Gender was evenly split; 42.6% had a university degree. Mean age 49.5 years. Participant was person who answered the phone provided he/she was 15 years or older.
creams (80%). In contrast, less than 1% of the respondents reported disposal of ointments and creams into the sewage, only 19% reported to have disposed of tablets and capsules in the sink or toilet and only 24% of the respondents disposed of liquid formulations in the garbage. Furthermore, the German study (Gotz and Keil, 2007) reported that 32% of the participants disposed of their unused liquid formulations ‘always’, ‘usually’ or ‘sometimes’ in the toilet or sink, whilst only 10% of solid dosage forms were disposed of in the toilet or sink. Moreover, the type of medication may also influence consumer disposal according to a nationwide Dutch survey in the 1990s (Blom et al., 1996). One of the questions asked of the participants during the survey interview was “How do you dispose of particular classes of medication, such as cough medicine, painkillers, and skin ointment of antibiotics?” Whilst 52% and 42% of the participants said antibiotics and painkillers should be returned to the pharmacy respectively, 27% would dispose cough medications in the garbage or toilet and 26% in the sewage system. Only 27% of participants would return cough
Table 2 Methods used to dispose of unused medication as reported by the peer-reviewed literature. Method of disposal Locality (with Toilet or sink formulations or setting)
Garbage
Other (stated)
Return to pharmacy
Sample size (n)
1986 Ridout et al. 1996 Blom et al.
United Kingdom Netherlands
46% 3%
14% 9%
17% 58%
443 2154
1996 Kuspis and Krenzelok
United States
35.4%
54%
1.4%
500
1996 Sullivan and George 2005 Bound and Voulvoulis
United Kingdom United Kingdom
27% 11.5%
15% 63.2%
34% 21.8%
400 392
2006 Abahussain et al. 2006 Seehusen and Edwards 2007 Abahussain et al. 2007 Gotz and Keil
11.2% 53.8% (toilet) 35.2% (sink) 2.0% 1% (always), 2% (usually), 7% (sometimes) and 6% (rarely) 10% (always), 8% (usually), 13% (sometimes) and 12% (rarely) 8% 6% – 55%
76.5% – 97% 7%a (always), 9%a(usually), 14%a (sometimes) and 13%a (rarely)
11.9% 300 22.9% 301 – 200 29%a(always) 11%a(usually) and 1306 15% a(sometimes) 11%a(rarely)
89% 87% 50% 24%
2% (burning unused medications) 12.5% (burning unused medications) 50% (burning unused medications) 0.7% (give away or burn)
3% – – 17%
200b
19%
51%
2.4% (give away or burn)
24%
452
b1%
80%
2.4% (give away or burn)
13%
452
2009 Kotchen et al.
Kuwait United States Kuwait Germany (solid medications) Germany (liquid medications) Lithuania (towns) Lithuania (towns) Lithuania (countryside) New Zealand (liquid medicines) New Zealand (tablets and capsules) New Zealand (ointments and creams) United States
15% (kept medicines) 16% (chemical waste) and 6% (kept medicines) 7.2 (kept medicines) and 2% (finished medications) 15% (kept medicines) 3.5% (waste sites or other disposal facility) 8.5% (give to friend) 14% (returned to healthcare provider) 0.5% (give to friend) 23% a (recycled alongside cardboard and plastics) and 15%a(toxic waste bins)
28%
45%
6%
1005
2009 Persson et al.
Sweden (2001 survey)
–
7%
41%
1000
2009 Persson et al. 2009 Persson et al.
Sweden (2004 survey) Sweden (2007 survey)
– –
3% 3%
5% (hazardous waste centre), 12% (store at home) and 4% (unspecified method) 48% (kept medicines) 2% (recycling station) 1% (health centre) 54% (kept medicines) 55% (kept medicines)
42% 43%
1000 1000
2007 Gotz and Keil 2007 Krupiene and Dvarioniene 2007 Krupiene and Dvarioniene 2007 Krupiene and Dvarioniene 2009 Braund et al. 2009 Braund et al. 2009 Braund et al.
a b
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Year of study and author(s)
No differentiation between dosage forms in disposal routes other than toilet/sink. Total number of participants from towns, suburbs/settlements and countryside.
295
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medications to the pharmacy. Therefore, it is likely people return unused medications considered to be more harmful to pharmacies. 4.2. Influence of environmental awareness on medication disposal methods The association between environmental pollution and improper medicines disposal is seemingly a recent concept even to health professionals. In the 1990s, it was acceptable for pharmacists in the United States to advise patients to dispose of unused medications in the their own sink, toilet or garbage if they did not or could not return their medications to the pharmacy (Kuspis and Krenzelok, 1996). It has been reported as recently as 2006 that 35% and 21% of the participants in a US study (Seehusen and Edwards, 2006), thought that it was appropriate to flush medications down the sink or toilet respectively. Some studies reported in the literature have also asked whether participants knew of the environmental risks associated with improper disposal of medication. In a Swedish randomized telephone survey (Persson et al., 2009) there was no reported prevalence of any participant flushing unused medication down the toilet or sink in the 2007 survey, and most opted to store their unused medication or return the medications to the pharmacy for disposal. Indeed, participants that returned unused medication to the pharmacy were asked why they did so. In 2007, 42% of the participants said they were worried about environmental pollution by medications compared with only 26% giving the same response in 2001. Even in a Dutch study from the 1990s 72% and 80% of the participants who stated they returned unused medication to a pharmacy or to a chemical waste facility respectively, did so because they were concerned about the environment (Blom et al., 1996), whilst the participants who disposed unused medication predominantly via the sewage or the garbage did so because it was convenient. Furthermore, a recent study in the United States (Kotchen et al., 2009) asked participants whether they were aware that pharmaceuticals have been detected in the environment. Forty-three percent of participants stated they were aware of this fact and these participants were more likely to dispose of medications in a manner that reduces potential environmental pollution (i.e. return unwanted medications to pharmacies). However, improper disposal was still prevalent in environmentally- aware participants in this US study (38.7% in trash; and 23.2% in toilet or sink), which suggests that awareness of environmental issues surrounding medicines disposal only partially accounts for peoples' medicine disposal habits. It is apparent that environmental awareness may not be associated with educational status. In Kuwait (Abahussain and Ball, 2007) 62% of the study sample were university graduates or had some form of tertiary education but 97% of the study participants stated they would dispose of their unwanted medications in the garbage. From this data, medicine disposal habits are clearly influenced by environmental awareness, but this is not the sole factor which will determine how patients discard their unused medications. 4.3. The availability of formalized protocols for medicines disposal The availability of official state guidelines for disposal of unwanted medication is a major influence on how people dispose of unused pharmaceuticals. From the results of two UK studies (Table 2) it can be seen that more people returned unused medication to pharmacies in 1996 compared to 1986 (Ridout et al., 1986; Sullivan and George, 1996). This may be due to proper disposal of medication campaigns promoted by the Royal Pharmaceutical Society of Great Britain in the 1990s which advocated that patients should return any unused, excess and/or expired medications to pharmacies for proper disposal. Conversely, there were no official guidelines for pharmaceutical disposal set by the Food Drug and Administration (FDA), state
pharmacy boards, or the Environmental Protection Agency (EPA) in the US in the 1990s (Kuspis and Krenzelok, 1996) and this situation may have led people in the US to dispose of pharmaceuticals conveniently in the toilet, sink or garbage at that time. No official guidelines for disposal of unwanted medications exist in Kuwait (Abahussain and Ball, 2007) and 54% of the responding participants in an earlier Kuwaiti study (Abahussain et al., 2006) thought it was appropriate that the option of returning medicines in pharmacy dropboxes should be available to the public. Furthermore, many people thought it was appropriate that medicines should be disposed of in secure bins in shopping malls (21%) and home collection schemes (15%). In addition 40% of the responding participants suggested that public knowledge of how unused medications should be disposed of was lacking in Kuwait. However, no medications were collected in 2007 when a pilot collection scheme was trialed with survey participants in Kuwait (Abahussain and Ball, 2007). Nevertheless this latter study surveyed participants from middle to high socialeconomic groups, whereas the previous 2006 study (Abahussain et al., 2006) surveyed hospital patients in a Kuwaiti government hospital who were from lower social-economic groups. It could be that these patients may not have been able to afford expensive methods of medicines disposal and may have been more dependent on the state to deal with waste medicines compared to the situation for middle or upper class participants. However this study was undertaken in a hospital and so there is always the likelihood that patients were providing answers that they thought were ‘correct’ and establishing a proper medicines disposal system and returning medication to pharmacies for disposal are seemingly appropriate answers even to participants unaware of proper disposal methods. In Lithuania most people dispose of unwanted medications in the garbage or burn them (Krupiene and Dvarioniene, 2007). Whilst backyard burning of pharmaceuticals may render pharmaceuticals to be inactive (Peake and Braund, 2009), complete combustion of the pharmaceuticals is never guaranteed, and residues from the incineration site may still be discharged into the environment albeit in partially or fully oxidized forms. This may be a particular consideration for people in the countryside, where the natural environment is in closer proximity to burn sites and hence the products of combustion arising from burning. Pharmacies in Lithuania are poorly utilized as drug collection depots (Krupiene and Dvarioniene, 2007). It was reported that only 3% of the respondents residing in towns returned unwanted medication to pharmacies. Many may have failed to return medications to pharmacies because many felt stigmatized or stupid when seen carrying medications back into the pharmacy. As many as 73% of the study sample did not think pharmacies were able to take back unwanted medication. In addition, many pharmacies may have actively refused to accept returned medications and thus added confusion to the ‘proper’ method for disposal of unwanted medications. Some state laws in the United States actually prevent pharmacies from accepting unwanted medications (Seehusen and Edwards, 2006) particularly controlled substances as these medications may be diverted (Vivian, 2009). Controlled medications are a major hurdle in the US for the establishment of a convenient, cost-effective nationwide disposal protocol — such substances have to be inventoried by law enforcement even in many small pilot collection programs me in the US (Glassmeyer et al., 2009) and this adds extra running costs to the system. The current FDA recommendations, in fact, list 26 ‘dangerous’ medications which should be flushed down the toilet (Mitka, 2009). For all other medications the FDA has recommended that, if a ‘take-back’ or ‘mail-back’ program is unavailable then unused solid medications should be crushed with an unpalatable substance, such as cat litter, mixed, and disposed in the garbage in a leakproof, sealed container (Glassmeyer et al., 2009). Whilst such practices may reduce the likelihood of poisonings and diversion (Inciardi et al., 2009), the long term consequences associated with the exposure of the environment to such pharmaceuticals from the sewage or landfill is at
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present unknown. Furthermore it has been reported that the White House and FDA have offered conflicting information on medication disposal which may have added to confusion (Erickson, 2010). People who visit pharmacies and healthcare centers on a regular basis may be more educated about returning medication to pharmacies; the lack of pharmacy access to countryside dwellers in Lithuania may also be another reason why these people living in this country did not return medication to pharmacies. In the United States, it was shown that patients who were counseled to properly return unused medications to pharmacies and healthcare providers were more likely to do so (Seehusen and Edwards, 2006). The need for public education on disposal of pharmaceuticals is further emphasized by a recent New Zealand study (Braund et al., 2009) where nearly one-quarter of the participants surveyed stated they kept unwanted medicines around the household because they did not know what to do with them. Germany is another country that is reported as having no state-run disposal system, and guidelines for disposal of dosage forms are different between regions (Gotz and Keil, 2007). Some prescribed medicines have disposal instructions on the packaging; however, this does not apply to all pharmaceuticals in Germany. It has been recommended that standardized and legally binding protocols for drug disposal are set up in this country but many of the participants stated that they were unwilling to pay for the institution of an official medications disposal system. All solid wastes in garbage are subjected to high temperature incineration in Germany and thus the likelihood for medicinally rich leachate to be discharged from a landfill is unlikely. Subsequently much environmental pollution will result entirely from the medicines that are disposed of in the sewage system in Germany. At least 55% of the participants remarked that they sometimes returned their unused medication to pharmacies, suggesting that many people may know that it is appropriate to return unused medications to pharmacies but instead they found it more convenient to continue to dispose of pharmaceuticals at home. Indeed, it has been reported that laziness may also be a contributing factor for a lack of medication returns to pharmacies in Sweden (Persson et al., 2009). However, it was not possible to ascertain the type and quantity of medications that were disposed of in the German study; or the actual frequency of disposal via the various methods reported by the participants, as this would have required a knowledge of whether patients are taking their medications and such compliance data were not recorded in this study. Ultimately, the cost of setting up a nationwide medicines disposal system accessible by the public may be substantial, but the low prevalence of improper disposal methods as reported in Sweden (Persson et al., 2009) is clearly influenced not only by the people's attitudes and knowledge of medicine disposal practices, but also the availability of a well-run disposal system. Since 1971 Sweden has an established reverse distribution system run by a major pharmacy wholesaler in conjunction with the state pharmaceutical association. Medicines returned to pharmacies are ultimately destined for incineration at high temperatures, and the residual deposited in specified landfills. It has been estimated that 73% of Swedish people eventually return unused medications to pharmacies. It can be said that in order for a ‘disposal and destruction’ system to be successful, it has to be used by the public. The effectiveness of the Swedish disposal system may, of course, only apply to Sweden; this could be the fact that Swedish people appear to be very compliant with state protocols, but if the same system was transferred to another country, different social attitudes to state protocols may render the system ineffective.
297
unused medication and how improper disposal methods may affect the environment. The most popular medicine disposal methods observed in many of the studies still have the potential to detrimentally pollute the environment. Confusion exists in different countries as many countries lack adequate guidelines for the ‘proper’ disposal of unused medications. Public services around the world, including government and health sectors, need to be more proactive about educating patients on how to use and dispose of medication in a more environmentally acceptable manner, and establish an official guideline that is relevant to their particular country. For certain parts of the world, proper disposal of unused medications may include schemes that allow patients to conveniently and discreetly return unused medication to a pharmacy, rather than discourage and embarrass patients for doing so. This may be particularly important in countries which offer free or subsidized medications and thus, there is an increased risk of accumulation and hoarding of unused medication. The establishment of formalized state-run collection and disposal systems that are cost-effective, easily accessible to the public and actually employing methods which completely degrade unwanted pharmaceuticals is of paramount importance as this avoids confusion about the ‘correct’ way to dispose of medications. A typical collection and disposal system may be set up to 1) collect unwanted medicines that have been returned to pharmacies or 2) collect the medicines directly from patients, depending on cost constraints and the willingness of patients to use the suggested system. To minimize discharge into the environment, the pharmaceuticals can then be completely destroyed by high-temperature incineration, and the ashes deposited in leakproof containers bound for specialized landfills dealing in pharmaceutical waste. Of course, it would be mandatory that consumers are willing to pay for the institution and running costs of such a system. Future directions for research in this area may include further evaluation of user-friendly and cost-effective means of returning unused medications to pharmacies, and the most effective and safe means for their ultimate disposal. Of course, one other alternative solution which has not been reviewed at all in this paper is for physicians to minimize their prescribing of excessive and unnecessary medication; such a practice would drastically reduce the medicines needing to be disposed of in used or unused forms and hence their potential environmental impact. In turn, pharmacists also have a role to play in ensuring that patients take all of their prescribed medications. Finally, it is clear from this review that the few studies that have been undertaken on disposal practices have involved only a small number of countries. For a more comprehensive and accurate picture of the global situation, further research needs to be undertaken in other countries, particularly those with large human populations and hence where pharmaceutical disposal practices may have a significant impact on the global environment. In addition, there has been little analysis of pharmacists' attitudes and methods for disposal of unused medication from pharmacies, which is another area that requires further investigation. Finally, as this review has shown, how people dispose of pharmaceuticals may depend on cultural and social differences, and this opens avenues for future studies on how these factors may impact on medication disposal habits. Overall, the limited collated evidence suggests there is a pressing need for increasing public awareness on the issue of medication disposal, and currently, patients, scientists, health professionals and government officials are all only starting to become aware of the various methods employed for unused medication disposal, and how these may impact on the environment.
5. Conclusion Acknowledgements The current evidence collated from a relatively small number of studies undertaken in different countries suggests that patients still very much lack the knowledge as to the proper disposal of their
Dr. Eike Breitbarth (Chemistry Department, University of Otago) for assistance in translating some of the literature written in German,
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