The opiate quasiwithdrawal syndrome in rhesus monkeys: comparison of naloxone-precipitated withdrawal to effects of cholinergic agents.

The effects of the cholinergic agents UM-1046 (3-cyclopropyl-methyl-1,2,3,4,5,6-hexahydro-8-hydroxy-6-methyl-3-benz azo cine hydrochloride) and physostigmine in normal rhesus monkeys were compared to naloxone-precipitated withdrawal in morphine-dependent subjects. The two cholinergic drugs produced effects that resembled one another, as well as some of the effects of naloxone in morphine-dependent subjects. The constellation of signs produced by the cholinergic drugs, while overlapping, was not identical to that produced by naloxone in opiate-dependent subjects. Although cholinergic agents produce many of the signs of opiate withdrawal syndrome in its complete manifestation involves many different neurotransmitter systems.