- Email: [email protected]
Re: Drugs, driving and sobriety tests
126 Journal of Clinical Forensic Medicine interactions have never been previously reported in the literature. Therefore, we hypothesize that buprenorphine and tramadol could present similarities, which may explain their potential interactions with benzodiazepines. In fact, it is possible to affirm that both have a l-opioid receptors affinity, are modulated by naloxone and undergo extensive oxidative metabolism by P450 cytochrome and inhibit the CYP3A. It is therefore possible to suggest that tramadol could interact pharmacokinetically with benzodiazepine in a similar manner as buprenorphine. Furthermore, this interaction could produce an addictive or synergic effect of tramadol and benzodiazepine on the CNS. This hypothesis would explain that death could occur even at low blood concentrations and even with non-lethal dose. To our knowledge, an interaction between tramadol and benzodiazepines has not been previously reported. Both drugs are already in widespread clinical use and are prescribed by general practitioners as well as in several other specialties. This pharmacokinetic drug interaction warrants further clinical investigation. Consequently, we suggest that physicians should be more aware when prescribing tramadol and benzodiazepines concomitantly. REFERENCES
2. Lee CR, McTavish D, Sorkin EM. Tramadol: a preliminary review of its pharmacodynamic and pharmacokinetic properties, and its therapeutic potential in acute and chronic pain states. Drugs 1993; 46: 313–340. 3. Subrahmanyam V, Renwick AB, Walters DG, Young PJ, Price RJ, Tonelli AP, Lake BG. Identification of cytochrome P-450 isoforms responsible for cis-tramadol metabolism in human liver microsomes. Drug Metab Dispos 2001; 29(8): 1146–1155. 4. Ono S, Hatanaka T, Miyazawa S, Tsutsui M, Aoyama T, Gonzalez FJ, Satoh T. Human liver microsomal diazepam metabolism using cDNA-expressed cytochrome P450s: role of CYP2B6, 2C19 and the 3A subfamily. Xenobiotica 1996; 26(11): 1155–1166. 5. Sproule BA, Naranjo CA, Brenmer KE, Hassan PC. Selective serotonin reuptake inhibitors and CNS drug interactions. A critical review of the evidence. Clin Pharmacokinet 1997; 33(6): 454–471.
Franck Clarot Bernard Proust E. Vaz Department of Forensic Medicine Rouen University Hospital Rouen 76031, France E-mail address: [email protected] Jean Pierre Goulle Pharmakinetic and Toxicology Laboratory Jacques Monod Hospital 76083 Le Havre, France
1. Musshoff F, Madea B. Fatality due to ingestion of tramadol alone. Forensic Sci Int 2001; 116: 197–199.
Ó 2003 Elsevier Science Ltd and APS. All rights reserved. doi:10.1016/S1353-1131(03)00039-7
Sir,
behaviour and then only in the highest dose level of the drug. However, FIT of the volunteers resulted in subjects being declared ‘‘unfit’’ on 11 occasions out of 56 (8 subjects). Therefore, using a simulated driving test, it was not possible to show any major impairment of driving ability and yet the FIT procedure would have failed 8 out of the 14 drivers on at least one occasion. The reason for this is highlighted in a recent study of marijuana and alcohol, separately and combined.3 The investigators concluded that cannabis impaired balance without detrimentally affecting a simulated driving task but that the impaired balance may trigger a false positive on a FIT. In the UK ‘‘impairment’’ to drive is not defined in law. The use of FIT and whether or not a subject ‘‘passes’’ or ‘‘fails’’ the tests is being used by the police as evidence of impairment. However, we have no evidence of how the performance on the various tests relates to driving ability or on how the performance of
Re: Drugs, driving and sobriety tests In their article ‘‘Drugs, driving and sobriety tests – review of recent developments’’ Stark et al.1 suggest that field impairment testing (FIT) is a suitable method for the detection of impaired driving due to drugs. The authors cite evidence that FIT can reliably identify drug use and can even identify the class of drug use in 90% of cases. However, they present no evidence that there is any correlation between a persons performance on any aspect of the battery of tests used in FIT and that persons ability to drive. The problem is illustrated by the Transport Research Laboratory study2 on the effects of cannabis on driving. In this study the investigators were only able to show that cannabis had a small detrimental impact on a single aspect of simulated driving
Correspondence 127 these tests varies across the population, at different times of day or night, by age of the driver, by medical condition etc. Without this information it is impossible for the courts to evaluate the information that is being presented to them. The very name of the procedure ‘‘Field Impairment Testing’’ leads to an erroneous assumption that driving impairment is being measured yet there is no clear evidence that this is indeed the case. In addition, a survey of police surgeons in Strathclyde found that 48% of the respondents expressed reservations about the FIT procedures.4 It is our belief that the use of these tests has led, and will continue to lead, to the arrest and conviction of motorists whose only crime is that they cannot ‘‘pass’’ the FIT procedure. Stark et al.1 are also aware of this problem and state ‘‘It would be desirable to have a yardstick so that those drivers who failed a given number of components on an individual test or failed a particular combination would be judged to be impaired’’. However this ‘‘yardstick’’ does not exist. Until it does, convictions based on the use FIT procedures should be considered unsafe.
2. Sexton BF, Tunbridge RJ, Brook-Carter N, Jackson PG, Wright K, Stark MM, Englehart K. The influence of cannabis on driving. Report TRL 477; 2000: Published TRL Ltd, UK (www.trl.co.uk/static/dtlr/pdfs/TRL477.pdf, accessed 21st February 2003). 3. Liguori A, Gatto CP, Jarrett DB. Separate and combined effects of marijuana and alcohol on mood equilibrium and simulated driving. Psychopharmacology 2002; 163: 399–405. 4. OKeefe M. Drugs and driving – standardized field sobriety tests: A survey of police surgeons in Strathclyde. J Clin Forensic Med 2001; 8: 57–65.
Atholl Johnston Professor of Clinical Pharmacology Barts and The London Queen Marys School of Medicine and Dentistry University of London, Charterhouse Square University of London London, EC1M 6BQ UK E-mail: [email protected] John Ramsey TICTAC Communications Ltd St Georges Hospital Medical School Cranmer Terrace London, SW17 0RE UK
REFERENCES 1. Stark MM, Tunbridge R, Rowe D, Fleming P, Stewart D. Drugs, driving and sobriety tests – review of recent developments. J Clin Forensic Med 2002; 9: 126–132.
Sir, Re: Letter to the editor: regarding lack of agreement on colour description in bruising Munang et al.1 have amply demonstrated the difficulty of accurately describing the colour of a bruise for forensic purposes. In 1990, Langlois and Gresham2 demonstrated that the only significant conclusion that could be drawn from the colour of a bruise, was that yellowness indicated a bruise more than 18 h old. Many years ago, as a new police surgeon, I sat in court, hoping to learn something from the evidence to be given by one of my elders and (I thought) betters. When he stated categorically that ‘‘The bruises on the subjects shoulders were caused by the straps of the rucksack he was wearing the day before’’, I left in disgust.
Ó 2003 Elsevier Science Ltd and APS. All rights reserved. doi:10.1016/S1353-1131(03)00033-6
My first textbook of Forensic Medicine, ‘‘Glaister’’,3 gives a specific timed sequence of colour changes, including yellow on the eighth to tenth day. Subsequent textbooks have become less and less didactic. Now, after 25 years experience, when asked the age of a bruise, I turn the question round, and ask how old it is thought to be. I then say whether I believe that its appearance is consistent with that figure, or older or younger. Often there are two versions of the story, and I say which version I prefer. I have adopted a similar policy when asked the time of death. I would suggest that adoption of these policies, would lead to less red faces in the witness box!
REFERENCES 1. Munang, Leonard, Mok. Lack of agreement on colour description between clinicians examining childhood
2. Lee CR, McTavish D, Sorkin EM. Tramadol: a preliminary review of its pharmacodynamic and pharmacokinetic properties, and its therapeutic potential in acute and chronic pain states. Drugs 1993; 46: 313–340. 3. Subrahmanyam V, Renwick AB, Walters DG, Young PJ, Price RJ, Tonelli AP, Lake BG. Identification of cytochrome P-450 isoforms responsible for cis-tramadol metabolism in human liver microsomes. Drug Metab Dispos 2001; 29(8): 1146–1155. 4. Ono S, Hatanaka T, Miyazawa S, Tsutsui M, Aoyama T, Gonzalez FJ, Satoh T. Human liver microsomal diazepam metabolism using cDNA-expressed cytochrome P450s: role of CYP2B6, 2C19 and the 3A subfamily. Xenobiotica 1996; 26(11): 1155–1166. 5. Sproule BA, Naranjo CA, Brenmer KE, Hassan PC. Selective serotonin reuptake inhibitors and CNS drug interactions. A critical review of the evidence. Clin Pharmacokinet 1997; 33(6): 454–471.
Franck Clarot Bernard Proust E. Vaz Department of Forensic Medicine Rouen University Hospital Rouen 76031, France E-mail address: [email protected] Jean Pierre Goulle Pharmakinetic and Toxicology Laboratory Jacques Monod Hospital 76083 Le Havre, France
1. Musshoff F, Madea B. Fatality due to ingestion of tramadol alone. Forensic Sci Int 2001; 116: 197–199.
Ó 2003 Elsevier Science Ltd and APS. All rights reserved. doi:10.1016/S1353-1131(03)00039-7
Sir,
behaviour and then only in the highest dose level of the drug. However, FIT of the volunteers resulted in subjects being declared ‘‘unfit’’ on 11 occasions out of 56 (8 subjects). Therefore, using a simulated driving test, it was not possible to show any major impairment of driving ability and yet the FIT procedure would have failed 8 out of the 14 drivers on at least one occasion. The reason for this is highlighted in a recent study of marijuana and alcohol, separately and combined.3 The investigators concluded that cannabis impaired balance without detrimentally affecting a simulated driving task but that the impaired balance may trigger a false positive on a FIT. In the UK ‘‘impairment’’ to drive is not defined in law. The use of FIT and whether or not a subject ‘‘passes’’ or ‘‘fails’’ the tests is being used by the police as evidence of impairment. However, we have no evidence of how the performance on the various tests relates to driving ability or on how the performance of
Re: Drugs, driving and sobriety tests In their article ‘‘Drugs, driving and sobriety tests – review of recent developments’’ Stark et al.1 suggest that field impairment testing (FIT) is a suitable method for the detection of impaired driving due to drugs. The authors cite evidence that FIT can reliably identify drug use and can even identify the class of drug use in 90% of cases. However, they present no evidence that there is any correlation between a persons performance on any aspect of the battery of tests used in FIT and that persons ability to drive. The problem is illustrated by the Transport Research Laboratory study2 on the effects of cannabis on driving. In this study the investigators were only able to show that cannabis had a small detrimental impact on a single aspect of simulated driving
Correspondence 127 these tests varies across the population, at different times of day or night, by age of the driver, by medical condition etc. Without this information it is impossible for the courts to evaluate the information that is being presented to them. The very name of the procedure ‘‘Field Impairment Testing’’ leads to an erroneous assumption that driving impairment is being measured yet there is no clear evidence that this is indeed the case. In addition, a survey of police surgeons in Strathclyde found that 48% of the respondents expressed reservations about the FIT procedures.4 It is our belief that the use of these tests has led, and will continue to lead, to the arrest and conviction of motorists whose only crime is that they cannot ‘‘pass’’ the FIT procedure. Stark et al.1 are also aware of this problem and state ‘‘It would be desirable to have a yardstick so that those drivers who failed a given number of components on an individual test or failed a particular combination would be judged to be impaired’’. However this ‘‘yardstick’’ does not exist. Until it does, convictions based on the use FIT procedures should be considered unsafe.
2. Sexton BF, Tunbridge RJ, Brook-Carter N, Jackson PG, Wright K, Stark MM, Englehart K. The influence of cannabis on driving. Report TRL 477; 2000: Published TRL Ltd, UK (www.trl.co.uk/static/dtlr/pdfs/TRL477.pdf, accessed 21st February 2003). 3. Liguori A, Gatto CP, Jarrett DB. Separate and combined effects of marijuana and alcohol on mood equilibrium and simulated driving. Psychopharmacology 2002; 163: 399–405. 4. OKeefe M. Drugs and driving – standardized field sobriety tests: A survey of police surgeons in Strathclyde. J Clin Forensic Med 2001; 8: 57–65.
Atholl Johnston Professor of Clinical Pharmacology Barts and The London Queen Marys School of Medicine and Dentistry University of London, Charterhouse Square University of London London, EC1M 6BQ UK E-mail: [email protected] John Ramsey TICTAC Communications Ltd St Georges Hospital Medical School Cranmer Terrace London, SW17 0RE UK
REFERENCES 1. Stark MM, Tunbridge R, Rowe D, Fleming P, Stewart D. Drugs, driving and sobriety tests – review of recent developments. J Clin Forensic Med 2002; 9: 126–132.
Sir, Re: Letter to the editor: regarding lack of agreement on colour description in bruising Munang et al.1 have amply demonstrated the difficulty of accurately describing the colour of a bruise for forensic purposes. In 1990, Langlois and Gresham2 demonstrated that the only significant conclusion that could be drawn from the colour of a bruise, was that yellowness indicated a bruise more than 18 h old. Many years ago, as a new police surgeon, I sat in court, hoping to learn something from the evidence to be given by one of my elders and (I thought) betters. When he stated categorically that ‘‘The bruises on the subjects shoulders were caused by the straps of the rucksack he was wearing the day before’’, I left in disgust.
Ó 2003 Elsevier Science Ltd and APS. All rights reserved. doi:10.1016/S1353-1131(03)00033-6
My first textbook of Forensic Medicine, ‘‘Glaister’’,3 gives a specific timed sequence of colour changes, including yellow on the eighth to tenth day. Subsequent textbooks have become less and less didactic. Now, after 25 years experience, when asked the age of a bruise, I turn the question round, and ask how old it is thought to be. I then say whether I believe that its appearance is consistent with that figure, or older or younger. Often there are two versions of the story, and I say which version I prefer. I have adopted a similar policy when asked the time of death. I would suggest that adoption of these policies, would lead to less red faces in the witness box!
REFERENCES 1. Munang, Leonard, Mok. Lack of agreement on colour description between clinicians examining childhood