Psychoactive drug interactions.

Interactions can arise from serial or simultaneous administration of 2 or more drugs. Interactions with other medications can enhance or diminish either the clinical usefulness of a drug, or its toxic effects. Interactions can arise from changes in absorption, protein binding, metabolism, excretion or activity at a common site of action. Drug interactions of clinical interest to psychiatrists are described. The drugs include: stimulants, neuroleptics, tricyclic antidepressants, monoamine oxidase inhibitors, lithium, anticonvulsants, and sedatives and hypnotics.