Clozapine (Clozaril - Sandoz), a dibenzodiazepine antipsychotic drug that has been available in Europe for many years, was recently approved for marketing by the US Food and Drug Administration. Because of its toxicity, the labeling for clozapine recommends using the drug only for schizophrenic patients who have not responded adequately to standard antipsychotic drugs or have had intolerable adverse effects.

The FDA has approved an inhalation powder formulation of loxapine (Adasuve – Teva), a first-generation antipsychotic long available in an oral formulation, for treatment of acute agitation related to schizophrenia or bipolar I disorder in adults. Adasuve is the first inhaled drug to be approved for this indication.

Zolpidem (Ambien - Searle), an imidazopyridine hypnotic available in Europe for several years, was recently approved by the US Food and Drug Administration for short-term treatment of insomnia.

Olanzapine (Zyprexa - Lilly), a thienobenzodiazepine that structurally resembles and binds to many of the same receptors as clozapine (Clozaril), is now available in the USA for treatment of schizophrenia and other psychotic disorders.

Quetiapine (Seroquel - Zeneca), a dibenzothiazepine derivative, has been approved by the FDA for treatment of schizophrenia and other psychotic disorders. It is a new addition to the 'atypical' antipsychotics, which include olanzapine (Zyprexa - Medical Letter, 39:5, 1997), risperidone (Risperdal) and clozapine (Clozaril). Atypical antipsychotic drugs generally are less likely to cause extrapyramidal symptoms than older drugs such as haloperidol (Haldol, and others) or the phenothiazines.

When patents expire on brand-name drugs and generic formulations become available, patients and managed care organizations may express a preference for the lower-cost generics. Are they equivalent to the brand-name product?

Ziprasidone (Geodon - Pfizer), a benzisothiazolyl piperazine, has been approved by the FDA for oral treatment of schizophrenia. An intramuscular formulation will probably be available in the near future.

Oral antipsychotic drugs used for treatment of schizophrenia, schizoaffective disorder, delusional disorder, and other manifestations of psychosis or mania are listed in Table 1. Parenteral antipsychotic drugs used for treatment of these disorders are listed in Table 2.

Clozapine (Clozaril - Sandoz), an antipsychotic drug, was first marketed in the USA three years ago (Medical Letter, 32:3, 1990). Because of its hematological toxicity, the US Food and Drug Administration approved the drug only for patients with schizophrenia who cannot tolerate or do not respond to standard antipsychotic drugs.

Aripiprazole (Abilify - Bristol-Myers Squibb/Otsuka), a quinolinone derivative, has been approved by the FDA for treatment of schizophrenia.