Benzodiazepines and drug abuse: clinical observations in chemically dependent persons before and during abstinence.

Sixty-nine (9.2%) of 750 consecutive persons entering a chemical-dependence treatment hospital had urinary evidence of benzodiazepines, a somewhat higher proportion than in the general adult American population. The 54 subjects in whose urine benzodiazepines, but not the other commonly abused psychoactive drugs, were detected, had varied clinical findings. One had used benzodiazepines only, 38 others were alcoholic benzodiazepine users, and 15 were multiple-drug (including benzodiazepines) users. Of these 54 only 6 (11%) developed major withdrawal symptoms. All 6 had used high doses of benzodiazepines (larger than or equal to 30 mg of diazepam or equivalent) daily. The risk of major withdrawal symptoms was about 50% for the high benzodiazepines--heavy alcohol group and zero for all other benzodiazepine-consuming patients. While clinical vigilance regarding withdrawal is urged for all benzodiazepine consumers, it is especially important amongst alcoholics, consuming high doses of benzodiazepines.