[Acute poisoning during substitution therapy based on high-dosage buprenorphine. 29 clinical cases--20 fatal cases].

OBJECTIVES

Buprenorphine has been an important advance in care for drug abusers, but the toxic risk may be fatal. We report here two original series of buprenorphine poisoning in opiate abusers on substitution therapy.

PATIENTS

The first series included 20 males and 9 females, aged 20-35 years (mean = 27.5) with non-fatal poisoning. The second series included 20 subjects (19 males, 1 female) aged 14-48 years (mean = 26.6) with a fatal outcome. All subjects were opiate addicts taking high-dosage sublingual buprenorphine formulation as substitution therapy.

RESULTS

Blood concentrations of buprenorphine were found in all cases to remain at a low level (1.0-2.3 ng/ml, m = 1.4 ng/ml, and 1.1-29.0 ng/ml, m = 8.4 ng/ml in non-fatal and fatal cases respectively). Almost all cases involved concomitant intake of psychotropic medications, especially benzodiazepines (18 non-fatal and 17 fatal cases).

DISCUSSION

These observations confirm previously reported data on the danger of buprenorphine-benzodiazepine combinations. Intravenous injection of crushed tablets also appears to be a risk factor (8 deaths and 10 non-fatal poisonings). This series highlights the need for improvement in the recently developed French program for substitution therapy with high-dosage buprenorphine in heroin addicts.