Benzodiazepine misuse and heroin addiction: data from a cohort of 40 overdose deaths

The mortality rate of heroin users (HUs) is far higher than that of the general population of the same age and sex. Overdose still represents a significant cause of death among HUs, especially if users are injecting drugs. Deaths attributed to overdose represented in literature are typically older, heroin-dependent males not in drug treatment at the time of death. The presence of other drugs, primarily alcohol and benzodiazepines (BZD), has been described as commontl detected at autopsy. Subjects who have previously developed opiod dependence abuse BDZs more frequently and at larger doses compared to BDZ mono-abusers. Drug users and alcoholics often use high doses of BDZ to soften withdrawal symptoms of the primary drug. To better describe this phenomenon we assessed alcohol and BDZ prevalence and typing in 40 overdose death, observed by an Italian forensic Medicine Department. the biological samples analyzed for this study were central blood and urine. All tests were performed using an ultra-sensitive liquid chromatography coupled with mass spectrometry in "tandem Mass Spectrometers". The demographic data of the cohort did not seem to differ from the Italian data on overdose presented by government agencies. The male / female ratio was 9:1 with a mean age slightly lower than the national one, 36 versus 37 years. Even in thi case, heroin overdose was markedly preponderant over cocaine. Low percentages of methadone in dead Hus have been found, yet another confirmation of the crucial role of this drug in counteracting the opioid overdose. Cocaine is confirmed as primary cause of death in 15% of the cohort. The BZDs were the substances most present in this sample. 62.5% of HUs were positive to one or more BZD. paradoxically, the BZDs were much more represented in this sample compared to antidepressants, mood stabilizers and antipsychotics. Opioid users should be educated about risks associated with poly-drug intake. Administration of BDZ in HUs may increase the risk of accidental fatal overdose. Prescribers should carefully consider pharmacological intervention alternative to BDZ when managing and treating opiate addiction. Last but not least, no presence of presription analgesic opioid was found in this sample. The pain killers epidemic seems not to have yet reached this part of Italy.