Imipramine and alprazolam treatment of lactate-induced acute endogenous distress in nonhuman primates.

The authors studied the response of 10 macaque monkeys to administration of sodium lactate, a panicogenic agent used in human panic disorder research, after treatment with the tricyclic antidepressant imipramine, the triazolobenzodiazepine alprazolam, or placebo. Both drugs effectively blocked the lactate-induced acute endogenous distress responses that had been reliably observed in the monkeys before drug treatment. Only alprazolam significantly reduced the occurrence of conditioned situational anxiety responses observed in the home cage. The alprazolam monkeys appeared to be sedated compared to the imipramine and placebo groups, and tremor and temporary exacerbation of anxious behaviors were observed during alprazolam withdrawal.