Clomipramine: an antiobsessional tricyclic antidepressant

Abstract

The chemistry, pharmacology, pharmacokinetics, adverse effects, and dosage of clomipramine hydrochloride are described, and clinical studies of the use of clomipramine in treating obsessive-compulsive disorder (OCD), other psychiatric conditions, and chronic pain are reviewed. Clomipramine hydrochloride, a tricyclic antidepressant, is a potent inhibitor of serotonin reuptake and may affect dopaminergic neurotransmission, suppress rapid eye movement sleep, produce changes in electrocardiograms, and elevate plasma prolactin. The drug is well absorbed from the gastrointestinal tract and undergoes extensive first-pass metabolism. Peak plasma concentrations occur three to four hours after a 150-mg oral dose. The mean elimination half-life is 39 hours. Some 66% of a dose is excreted in the urine, the remainder being eliminated in the feces. In clinical trials, clomipramine was significantly more effective than placebo, clorgiline, amitriptyline, imipramine, and doxepin in ameliorating the symptoms of OCD. Initial effects are seen at four weeks; improvement may continue for up to 18 weeks. Clomipramine may also be effective in treating panic attacks, phobias, depression, and chronic pain. The most common adverse effects of clomipramine are anticholinergic; others include nausea, seizures, and sexual difficulties. Interactions between clomipramine and barbiturates, haloperidol, monoamine oxidase inhibitors, and cigarette smoking have been documented. The usual initial adult dosage is 25-50 mg/day, titrated gradually to 250 mg/day if necessary. Clomipramine hydrochloride is a welcome new agent for the treatment of obsessive-compulsive disorder. Although its adverse-effect profile is like that of other tricyclic antidepressants, sexual dysfunction and seizures may be more frequent with this agent and limit its use.