Although evidence to date does not indicate any need to use lower doses of zolpidem in patients with renal disease, chronic renal impairment may reduce clearance of zolpidem. These patients should be closely monitored for drug accumulation and changes in pharmacokinetic parameters. Evidence of drug interactions between zolpidem and other CNS agents is limited. Some single-dose interactions have been studied but reactions may differ during chronic therapy. Singledose results indicate that haloperidol has no effect on the pharmacokinetics or pharmacodynamics of zolpidem.
Ethanol has an additive effect on psychomotor performance when given with zolpidem.
Other CNS depressant drugs may have cumulative effects when administered concurrently and they should be used cautiously with zolpidem. Loss of alertness was exacerbated when the drugs were administered concurrently. Interactions with other tricyclic antidepressants have not been studied, but additive drowsiness is also possible. Chlorpromazine and zolpidem together produced no change in pharmacokinetic parameters, but had an additive effect on loss of mental alertness and psychomotor function. Concurrent use of zolpidem with chlorpromazine or other phenothiazines should be undertaken with caution.