Toxicol Rev 2006; 25 (2): 79-85

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 1. Pharmacological Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 2. Buprenorphine-Associated Toxic Deaths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 3. Respiratory Effects of Buprenorphine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 4. Mechanisms of Interaction with Benzodiazepines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 5. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Buprenorphine is an opioid agonist-antagonist with a ‘ceiling effect’ for respiratory depression. Compared Abstract with methadone, its unique pharmacology offers practical advantages and enhanced safety when prescribed as recommended and supervised by a physician. Buprenorphine has been approved in several countries as an efficient and safe maintenance therapy for heroin addiction. Its use resulted in a salutary effect with a reduction in heroin overdose-related deaths in countries that implemented office-based buprenorphine maintenance. In France, however, where high-dose buprenorphine has been marketed since 1996, several cases of asphyxic deaths were reported among addicts treated with buprenorphine. Death resulted from buprenorphine intravenous misuse or concomitant sedative drug ingestion, such as benzodiazepines. In these situations of abuse, misuse, or in association with elevated doses of psychotropic drugs, buprenorphine may cause severe respiratory depression. Unlike other opiates, the respiratory effects from buprenorphine are not responsive to naloxone. However, the exact mechanism of buprenorphine-induced effects on ventilation is still unknown. The role of norbuprenorphine, the main N-dealkylated buprenorphine metabolite with potent respiratory depressor activity, also remains unclear. Experimental studies investigating the respiratory effects of combinations of high doses of buprenorphine and benzodiazepines suggested that this drug-drug interaction may result from a pharmacodynamic interaction. A pharmacokinetic interaction between buprenorphine and flunitrazepam is also considered. As there are many questions regarding the possible dangers of death or respiratory depression associated with buprenorphine use, we aimed to present a comprehensive critical review of the published clinical and experimental studies on buprenorphine respiratory effects. Heroin addiction remains a major concern worldwide and involvement in the illicit drug scene, by shifting the context of causes numerous fatalities.[1,2] Treatment of heroin addicts underheroin use into a medically supervised framework that offers more went a profound evolution with the development of maintenance support and greater possibilities of health promotion and social therapies including methadone and buprenorphine. The objective integration. Countries have chosen different strategies for mainteof the substitution programmes is to decrease intravenous drug nance and detoxification treatment of opioid dependence. Numerabuse-related mortality and morbidities. Treatments aim to reduce ous opioid molecules have been approved, different facilities for