Understanding medicines: conceptual analysis of nurses’ needs for knowledge and understanding of pharmacology (Part I)

Understanding medicines: conceptual analysis of nurses’ needs for knowledge and understanding of pharmacology (Part I)

Article Understanding medicines: conceptual analysis of nurses’ needs for knowledge and understanding of pharmacology (Part I) Helen L. Leathard The...

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Understanding medicines: conceptual analysis of nurses’ needs for knowledge and understanding of pharmacology (Part I) Helen L. Leathard

The advent of nurse prescribing in the United Kingdom (UK), albeit from a very limited formulary at first, provides a timely prompt for careful reflection on the extents and depths of understanding of medicines required by nurses for a variety of different purposes. This paper, which is the first of a two-part work, presents a conceptual analysis of what is required for patient care and support, pro re nata (as required) administration of medicines, protocol-directed administration of medicines (dependent prescribing), independent prescribing from the current Nurse Prescribers’ Formulary or independent prescribing from extended formularies or the entire British National Formulary. It includes review, with common examples, of presentational issues distinguishing between approved, generic names of medicines and trade or brand names, and some discussion of combination medicines; and of recent research that has demonstrated that patient care was improved when the bioscience knowledge of nurses increased. © 2001 Harcourt Publishers Ltd

Introduction Helen L Leathard BSc, PhD, Reader in Pharmacology and Human Physiology, Department of Nursing Studies and Centre for Health Research & Practice Development, St Martin’s College, Lancaster LA 1 3JD, UK. Tel.: 01525 384 615; Fax: 01524 384 581; E-mail: [email protected] c.uk Manuscript accepted: 19 December 2000

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The era of prescribing rights for nurses is dawning in the UK. Although the extent of prescribing rights for nurses is currently very limited, its advent provides a timely prompt for careful consideration of the understanding of medicines that is needed by nurses to enable them to fulfil their professional roles competently. Needs differ between groups of nurses, and an individual’s requirement will depend partly upon their current employment, partly upon their career ambitions and partly upon current and future legislation. The following conceptual analysis of this topic is derived from a process of critical reflection on experience gained during more than 20 years of teaching pharmacology, first to undergraduate

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doi:10.1054/nedt.2001.0553, available online at http://www.idealibrary.com on

medical students and latterly on pre-registration (BSc Nursing) and post-registration (BSc Nurse Practitioner; Dip HE High Dependency Nursing; District Nurse and Health Visitor Prescribing) nursing courses. Although based in the UK, the principles adduced below are likely to be widely applicable in nursing. This analysis will consider nurses’ requirements for the following purposes: ● ●





Patient care and support Pro re nata (as required) administration of medicines Protocol-directed administration of medicines (dependent prescribing) Independent prescribing from the current Nurse Prescribers’ Formulary (NPF, Mehta 1998, pp 694–696)

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Independent prescribing from extended formularies or the entire British National Formulary (BNF, Mehta 1998) BNF is published 6-monthly by the British Medical Association and the Royal Pharmaceutical Society of Great Britain. Volume 36, September 1998 is an illustrative example that coincided with the publication of the NPF.

The final section will summarize those aspects which my students have found most challenging and provide examples of helpful explanations of concepts that were found to be difficult.

Patient care and support Patient care and support is what nurses do on a regular basis, therefore preregistration education should underpin and facilitate this aspect of holistic treatment. There are three distinct aspects pertaining to pharmacology. One is the nurse’s health education role in providing advice and information to patients about their treatments. A second is the nurse’s responsibility to administer appropriate medicines correctly, in accordance with the United Kingdom Central Council for Nursing, Midwifery and Health Visiting ‘Guidelines for the Administration of Medicines’(UKCC 2000). A third relates to the nurse’s potentially invaluable role in helping to identify and make a preliminary evaluation of adverse drug effects at the earliest possible time. To provide optimal patient support in relation to medicines, nurses require sound and comprehensive knowledge of the actions and effects of all medicines being taken by patients in their care. They also need to know about common, clinically significant interactions between drugs, and the reasons for which the medicines are used. Integral to this is broad familiarity with the durations of courses of treatment (for the foreseeable future, fixed duration course or as required), dose frequency and what to do if one or more doses is or are missed. Such broad knowledge needs to be based upon secure understanding of the principles of pharmacokinetics (how bodies handle drugs) and pharmacodynamics (how drugs act upon bodies). Although retention of detailed information on a wide range of drugs is not feasible, nurses might reasonably have comprehensive understanding

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of those medicines that are commonly encountered in their particular practice and ability to look up appropriate information about others. It is also important for this role that nurses should have a clear understanding of the difference in definition between ‘drugs’ and ‘medicines’ (medicines being drugs formulated for clinical usage). The distinction between non-proprietary (generic or approved) names of medicines and combinations (which specify the active ingredients, and are the names under which medicines appear in the BNF) and proprietary (brand or trade) names which specify a particular pharmaceutical company’s product is also important. A useful indication of the status of a medicine’s name in authoritative texts is that non-proprietary names are treated as common nouns and have a capital initial letter only where they start a sentence. Brand names are treated as proper nouns and always have a capital initial letter and often some indication that the name is a registered trade mark. For example, paracetamol is a non-proprietary (generic, British approved) name whereas Panadol is one particular company’s brand of paracetamol. Generically-named drug combinations have their name prefixed by ‘co-’(combination), which draws attention to the complex nature of the medicine. Thus, co-codamol 8/500 and co-codamol 30/500 are generic names for combinations of paracetamol (500 mg) with 8 mg or 30 mg codeine, respectively. Proprietary products with the lower codeine content are available over the counter (OTC) either by the generic name, co-codamol, or as Panadeine, Paracodol or Parake, while those with the higher codeine content are prescription only medicines (POMs) and are marketed by different pharmaceutical companies as Kapake, Solpadol and Tylex. An individual drug may be marketed in a variety of formulations and doses under a range of brand names. Continuing the above example, paracetamol oral suspension 120 mg/5 mL (= Paediatric Mixture) is marketed by this generic name or as Cupanol Paediatric, sugar-free; Disprol Paediatric, sugar-free; Panadol sugarfree; Calpol Paediatric or Calpol Paediatric, sugar-free. Conversely, a single brand-named medicine may contain multiple active drug ingredients, any one of which may be a source of

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adverse effects or interactions. Typical contents of ‘cold and flu remedies’ are paracetamol (antipyretic analgesic), pholcodeine (antitussive, mild analgesic) and pseudoephedrine (nasal decongestant) with the addition of a sedative antihistamine for night-time use. With regard to unwanted or adverse effects, the nurse may detect physical signs of these through clinical observation of the patient. Good communication and history taking skills may also reveal symptoms which suggest an adverse reaction may be occurring, even if there is no obvious physical sign such as a rash or disturbance in heart rate. Anything serious or persistent or any uncertainties would need to be referred to the patient’s doctor or other prescriber and may merit reporting to the Medicines Control Agency and the Committee on Safety of Medicines through the yellow card system. An outline of this system in relation to nursing has been presented very lucidly by MorrisonGriffiths et al. (1998). It would be of interest to know how many preregistration nursing courses provide sufficient pharmacology education to meet these needs, and the outcome of research being sponsored by the English National Board for Nursing & Midwifery Education (ENB) is awaited with interest. Currently, at St Martin’s about 30 hours of the fulltime, preregistration BSc (Hons) Nursing degree, year 2 course in Human Biology Applied to Nursing is devoted to pharmacology linked to pathophysiology, but the preregistration Dip HE Nursing courses include much less pharmacology. The 3-h sessions that I have been allocated so far within the taught component of the ENB Nurse Prescribing course has been deemed insufficient for pharmacology in student evaluations, and is being reviewed. These allocations contrast quite markedly with the part-time, postregistration BSc (Hons) Nurse Practitioner degree which has an Applied Pharmacology double module with 50 hours in class and a further 20 with a clinical mentor. A prerequisite Human Health & Disease double module provides the necessary physiology and pathophysiology bases for the pharmacology. Designated hourage alone, does not indicate the adequacy or otherwise of the provision. Some recent, sound and relevant research demonstrates clearly, however, that more pharmacology education correlates with better knowledge (Ives

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et al. 1996) and clinical practice (Jordan & Hughes 1998). Ives et al. (1996) studied the actual and selfrated pharmacology knowledge of first year registered, graduate nurses in Victoria, Australia using a postal questionnaire. The findings demonstrated that there was a very wide range of extent of knowledge of pharmacology as assessed by multiple-choice questions (test scores ranged from 16% to 92%), with respondents who had participated in a graduate year program attaining higher test scores than those who had not. The means by which their pharmacology education had been delivered varied considerably and respondents valued their practical, clinical experience more highly than theory sessions as a means of gaining knowledge; emphasising the importance of relating theory to practice. Their ability to assess this is, however, questionable because self-rating of knowledge correlated with their test scores only in relation to therapeutic effects. They overestimated their knowledge of drug administration and legal aspects by considerable margins and somewhat overestimated their knowledge of adverse effects, but underestimated their knowledge in relation to client education. These findings can, therefore, be interpreted as demonstrating that clinical experience reinforces learning of those topics that are subject to discussion and critical appraisal in the workplace. Experience has less impact, however, on those topics where competence is assumed but is less subject to scrutiny by colleagues or clients. More recently, Jordan and Hughes (1998) have published a very substantial study of the impact on nursing practice of a part-time postregistration diploma in nursing course in Wales, that included 100 taught hours of applied physiology which clearly included pharmacology. Examples taken from ‘academic diaries’ kept by their subjects for 6 months (recording instances of the course affecting working practices), together with findings from questionnaires and interviews demonstrated that most students were applying their new knowledge in practice. Their participation in interprofessional discussions and team decisions increased, as did their ability to understand, assess and question medical decisions. It was evident that the quality of their caring for patients improved but, interestingly and challengingly, diverse inter- and

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intra-professional attitudes and structural constraints negated the potential for this to enhance their career prospects. Further exploration of this last crucially important point is beyond the scope of the present paper. What is important is that this research demonstrated that patient care was improved when the bioscience knowledge of nurses increased.

Pro re nata administration of medicines Administration of medicines by nurses to patients on an ‘as required’ basis occurs only in a limited range of clinical situations and relates to few groups of drugs, postoperative analgesia being a prime example. In addition to the extent of knowledge and understanding described above, those involved in pro re nata (p.r.n.) administration of medicines will need to understand the relative merits and disadvantages of regular, compared to intermittent, dosage and will need to be competent in helping patients to assess their requirements. If a range of doses and frequencies is indicated on the p.r.n. prescription the nurse will need good understanding of the signs and symptoms of under-treatment and over-dosage so that this information can be used in reaching concordance with the patient resulting in optimal treatment. Further, if more than one medicine is available p.r.n. (as in balanced analgesia involving opioids, antiemetics and non-steroidal anti-inflammatory drugs) it is essential that the nurse also understands something of the different modes of action of the different drug groups and the implications of this for optimal therapeutic benefit with minimal adverse effect.

Supply and administration under group protocol This increasingly prevalent practice is currently ‘grey’ from a legal viewpoint in the UK, but might be clarified and formalized by a governmental response to Review of Prescribing, Supply & Administration of Medicines (Crown 1999). The term ‘group protocol’ has been defined and explained by that review team as: . . . a specific instruction for the supply or administration of named medicines in an

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identified clinical situation. It is drawn up locally by doctors, pharmacists and other appropriate professionals, and approved by the employer, advised by the relevant professional advisory committees. It applies to groups of patients or other service users who may not be individually identified before presentation for treatment (Crown 1998). Legal responsibility for prescribing lies with those who sign the protocol, but the nurse applying the protocol in practice will have responsibilities consistent with the UKCC guidance on Scope of Professional Practice (1992). Potential usages range from minor adjustments to insulin, antihypertensive drug or anti-asthma drug dosages in nurse-led special clinics to initiation and adjustment of various protocolspecified treatments in hospital settings. From the pharmacological perspective it can be viewed as a variant of p.r.n. administration, mandating equivalent pharmacological knowledge and understanding. When, however, a protocol specifies multiple drug use or when the protocol is applied to patients with additional continuing medications there is a need for fuller understanding of the pharmacology. Actions and effects, the modes of action – at least at a basic level, pharmacokinetics, and possibilities for clinically-significant pharmacodynamic or pharmacokinetic interactions of all of a patient’s drugs will need to be understood. The requisite knowledge and understanding, therefore, approaches that needed for independent prescribing from extended formularies or any of the BNF.

Prescribing from the current nurse prescribers’ formulary The Nurse Prescribers’ Formulary (see, for example in Mehta 1998) is very simple from the perspective of pharmacology education requirements, and this has been discussed by Courtney and Butler (1998) in the light of experience from the first demonstration sites (Luker et al. 1997). The medicines listed either do not penetrate into the systemic circulation in significant quantities or they are available ‘over the counter’. They are, therefore, relatively safe if prescribed according to recommendations and

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are unlikely to interact adversely with other medicines a patient may be taking. In addition to the extent of knowledge and understanding of pharmacology recommended above for other forms of practice, further learning is required in two main areas: namely in relation to integumentary and alimentary systems functioning. For products being used topically on the skin, there needs to be good understanding of the factors that influence rate and extent of penetration of pharmacologically active agents into and through the skin. There needs to be an awareness of the degree of risk from active concentrations being reached in the systemic circulation, and precautions to be taken against this risk. The prescription of agents for local action within the alimentary tract requires good understanding of the mechanisms of action of the agents in relation to the complex functioning of the tract. Lactulose and senna, for example, are relatively inert in the upper gastrointestinal tract and their effectiveness depends upon the release of active products by the action of colonic bacteria. This is why at least 6–8 h usually elapses before the urge to defaecate is stimulated, and why these agents should be prescribed for administration either at bedtime or early morning but not late afternoon or evening. Additionally, it can be predicted that these laxatives are unlikely to be fully effective in anyone taking concurrent antibacterial drugs. The possible challenges to safety and effectiveness of all orally administered drugs, that are posed by nausea, vomiting, constipation, diarrhoea, intestinal obstruction or gastrointestinal side-effects of concurrent medications should also be known. When prescribing, for those entitled to free prescriptions, drugs that are available over the counter it is essential that the nurse has, at least, very good understanding of all the information provided with the product.

body. Anyone authorised to prescribe any such medicines will require an extensive course in pharmacology and clinical pharmacology such as those currently delivered to medical students. In addition to the pharmacology content specified above, any such course will need to engender understanding of mechanisms of action of drugs and groups of drugs (at receptor and enzyme interaction level, if not in biochemical detail) and of systemic factors that influence the concentrations and durations of action of the agents in the circulation and target tissue(s). These will include examination of the reasons for differences between actions, effects and durations of action between related drugs where these factors influence usage; and various influences of age and disease states on safety and effectiveness of the drugs. Potential prescribers will also need to understand the main aspects of drug discovery, development and evaluation and be able to appraise critically clinical trial data and promotional literature. From this conceptual analysis it can be concluded that the extent of knowledge and understanding of medicines needed by nurses varies considerably with their practice responsibilities. So long as medicines constitute a substantial component of health care and nurses continue to develop expanded roles in caring for patients there will be commensurate increases in their need for understanding of pharmacology to underpin nursing practice securely. The following paper illustrates what will be desirable ultimately, discusses some inherent challenges and offers some suggestions for coping with difficulties likely to be encountered.

Prescribing from extended formularies or the entire UK national formulary

References

It seems inevitable that any significant extension of the Nurse Prescribers’ Formulary will include drugs that enter the systemic circulation and become available for distribution throughout the body and subject to the metabolic processes of the

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Acknowledgements

I am pleased to thank Dr Shane Bullock, Dr Michael Cook and Dr Michael Walsh for their invaluable comments on typescripts of this paper.

Crown J 1998 Review of Prescribing, Supply and Administration of Medicines: A report on the supply and administration of medicines under group protocols. Department of Health, London Crown J 1999 Review of Prescribing, Supply & Administration of Medicines. Final Report. Department of Health, London Courtney M, Butler M 1998 Nurse prescribing – the knowledge base. Nursing Times 94 (1): 40–42

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Ives G, Hodge K, Bullock S, Marriott J 1996 First year RNs’ actual and self-rated pharmacology knowledge. Australian Journal of Advanced nursing 14(1): 13–18 Jordan S, Hughes D 1998 Using bioscience knowledge in nursing actions, interactions and reactions. Journal of advanced Nursing 27: 1060–1068 Luker K A, Austin L, Hogg C 1997 Evaluation of Nurse Prescribing: Final Report and Executive Summary. University of Liverpool, Liverpool Mehta D K 1998 (Executive Editor) British National Formulary (BNF) Volume 36 British Medical

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Association and the Royal Pharmaceutical Society of Great Britain Morrison-Griffiths S, Pirmohamed M, Walley T 1998 Reporting of adverse drug reactions: practice in the UK. Nursing Times 94 (10): 52–54 UKCC 2000 Guidelines for the Administration of Medicines United Kingdom Central Council for Nursing, Midwifery and Health Visiting UKCC 1992 Scope of Professional Practice. United Kingdom Central Council for Nursing, Midwifery and Health Visiting

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