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.