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.

The FDA has required the manufacturer of the secondgeneration antipsychotic quetiapine (Seroquel) to add a warning to the labeling saying that use of the drug should be avoided in combination with other drugs that prolong the electrocardiographic QTc interval (Table 1). The warning is based only on postmarketing reports of QT-interval prolongation in patients who overdosed on the drug, had concomitant illness, or were taking other drugs known to cause electrolyte imbalances or increase the QT interval. QT prolongation can lead to torsades de pointes, a potentially fatal cardiac...

Augmentation with a second-generation (atypical) antipsychotic is a treatment option for patients with major depressive disorder (MDD) whose symptoms persist following antidepressant monotherapy. Aripiprazole (Abilify), olanzapine in a fixed-dose combination with fluoxetine (Symbyax), and extended-release quetiapine (Seroquel XR) have been approved by the FDA for such use.

The FDA has approved the atypical antipsychotic pimavanserin (Nuplazid – Acadia) for treatment of hallucinations and delusions associated with Parkinson's disease. It is the first drug to be approved in the US for this indication.

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.

A recent supplement to the Journal of Clinical Psychiatry, titled "The Expert Consensus Guideline Series: Optimizing Pharmacologic Treatment of Psychotic Disorders," concluded that most experts endorsed use of second-generation (atypical) antipsychotics rather than first-generation drugs, with risperidone (Risperdal - Janssen) the top choice for first episodes, multiple episodes or switches from another drug (JM Kane et al, J Clin Psychiatry 2003; 64 suppl 12:5). The supplement was sponsored by Janssen.

Aripiprazole (Abilify - Bristol-Myers Squibb/Otsuka), a second-generation (atypical) antipsychotic drug, was approved by the FDA in 2002 for treatment of schizophrenia and more recently for bipolar disorder as well. It has been promoted as causing fewer adverse effects than other antipsychotics, without sacrificing efficacy.

The FDA has approved lurasidone (Latuda - Sunovion), a new second-generation antipsychotic, for oral treatment of schizophrenia in adults.

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.

The oral second-generation antipsychotic drug lumateperone (Caplyta – Intra-Cellular Therapies), which was approved by the FDA in 2020 for treatment of schizophrenia, is now approved for use as monotherapy or as an adjunct to lithium or valproate for treatment of depressive episodes associated with bipolar I or II disorder in adults.