More than 50 years ago, the first antipsychotic medications appeared in the United States. While these drugs -– fluphenazine, haloperidol, chlorpromazine, and others — were effective in treating a variety of psychiatric conditions, their safety and tolerability presented many drawbacks. It was not until the 1990s when a new class of antipsychotic medications emerged that presented a decreased risk of serious side effects. The newer class of so-called atypical antipsychotics — as opposed to the first-generation “typical” or “conventional” drugs — has not had a new member in more than a decade. Now, the US Food and Drug Administration (FDA) has approved the first new atypical antipsychotic in many years.

Asenapine is an atypical antipsychotic drug approved for the acute treatment of schizophrenia and the acute and extended treatment of mania associated with bipolar disorder. It is indicated for first-line treatment of both conditions, and is the first drug to receive approvals for both conditions simultaneously. The approval of asenapine follows clinical trials evaluating the drug’s efficacy in more than 3000 patients with schizophrenia or bipolar mania. Safety data was evaluated in trials including more than 4500 patients. Some of the trials lasted longer than 2 years.

In studies evaluating the efficacy in acute schizophrenia, doses of 5 mg of asenapine given twice daily were superior to placebo in treating the symptoms of schizophrenia. Doses of 10 mg twice daily significantly reduced mania symptoms associated with bipolar disorder, compared with placebo. Asenapine was found to be non-inferior to other standard atypical antipsychotics used to treat the same conditions.

Like other atypical antipsychotics, asenapine presents a decreased risk of serious side effects compared to typical antipsychotics, but still has the potential for adverse events, including weight gain, extrapyramidal symptoms, and the metabolic syndrome. In head-to-head comparisons, these risks were reduced with asenapine compared to other atypical antipsychotic drugs. Somnolence, dizziness, and movement disorders were also reported with asenapine.

All atypical antipsychotics, including asenapine, carry a black-box warning alerting prescribers and consumers to the risk of death associated with the off-label use of atypical antipsychotics to treat psychotic symptoms associated with dementia. While many clinicians and patients attest to the effectiveness of atypical antipsychotics for treating delirium, their use has never been thoroughly studied or verified. At best, the scientific evidence is inconclusive in this situation.

Asenapine is the first in a handful of new atypical antipsychotic drugs that will likely be appearing on the market in the near future. After more than a decade, clinicians will now have new options to manage their patients’ symptoms.

Asenapine is manufactured by Schering-Plough and will be marketed under the name “Saphris.” It will be available by the end of 2009.

References

Bishara, D., & Taylor, D. (2008). Upcoming Agents for the Treatment of Schizophrenia Drugs, 68 (16), 2269-2292 DOI: 10.2165/0003495-200868160-00002

Peritogiannis, V., Stefanou, E., Lixouriotis, C., Gkogkos, C., & Rizos, D. (2009). Atypical antipsychotics in the treatment of delirium Psychiatry and Clinical Neurosciences DOI: 10.1111/j.1440-1819.2009.02002.x

FDA News Release: FDA Approves Saphris to Treat Schizophrenia and Bipolar Disorder. 14 August 2009.