Loxapine: a review of its pharmacological properties and therapeutic efficacy as an antipsychotic agent.

Loxapine is a dibenzoxazepine, tricyclic compound recommended for the treatment of acute and chronic schizophrenia. In its therapeutic effectiveness and profile and incidence of side-effects, loxapine closely resembles the traditional antipsychotic agents. Although loxapine has tended to be less effective than some standard antipsychotic drugs in a few short-term (3 to 4 weeks) studies, it has been superior to a placebo and about as effective as chlorpromazine, haloperidol, trifluoperazine or thiothixene when evaluated after 4 to 12 weeks. Like the phenothiazine (e.g. chlorpromazine) and butyrophenone (e.g. haloperidol) antipsychotic agents, loxapine causes a high incidence of extrapyramidal reactions. Sedation occurs frequently, especially during early stages of treatment. Other, less common side-effects such as anticholinergic effects (dry mouth, blurred vision, etc.), hypotension, tachycardia and precipitation of epileptic seizures, which occur with the older antipsychotic drugs, have also been reported with loxapine.