Abuse and paradoxical effects of analgesic drug mixtures.

1 In patients with chronic pain, two types of analgesic drug dependence occur, that is, dependence of the barbiturate-type and of the morphine-type. Eighty cases of analgesic drug dependence of the barbiturate-type were examined. All these patients were dependent on drug combinations, not a single patient being on one analgesic alone. 2 Psychotropic agents were found to be the common pharmacological denominator of all abused preparations. These findings confirm the hypothesis that the addition of psychotropic or dependence-producing substances to analgesics is the crucial factor in the complex of mild analgesic drug abuse. 3 One group of patients with chronic pain, who were dependent on analgesic drug mixtures, had both lowered experimental pain thresholds and tolerances. After drug withdrawal, these parameters showed a tendency to increase in some patients.