By Michael Hirsch, M.D.
Featured in Harvard Mental Health Letter, June 2001
Ziprasidone (Geodon) is the most recent "atypical" antipsychotic medication to be approved by the FDA for the treatment of schizophrenia, the most serious common brain disorder of young adults. The atypical drugs differ from the older, "conventional" antipsychotic medications, which produce their therapeutic effects by blocking receptors for the brain neurotransmitter dopamine. Dopamine blockade in certain brain regions reduces the delusions, hallucinations, and disordered thinking characteristic of schizophrenia. But in other regions it may cause apathy and body movement disorders, such as agitation and muscle spasms. The atypical antipsychotics ‹ including clozapine, risperidone, olanzapine, quetiapine, and now ziprasidone ‹ also target receptors for other neurotransmitters, including serotonin, thereby mitigating the side effects of dopamine blockade while preserving the therapeutic effects
The recommended dose of ziprasidone is 80-160 mg daily, taken twice a day at meals (it is absorbed much better with food). Controlled experiments with more than 1000 patients have shown that it is effective, and like the other atypical drugs has little tendency to cause body movement disorders. Most patients are reasonably comfortable taking it, but it does have side effects, including nausea, headache, constipation, and dizziness. Some patients suffer insomnia or, less often, fatigue.
In addition to its antipsychotic effect, ziprasidone may relieve depression and anxiety in some patients. But its most important advantage is that, unlike most other antipsychotic drugs and especially other atypical drugs, it does not cause patients to gain weight. Among patients taking antipsychotic medications, excessive weight gain, as much as a pound a week, is a serious danger to health, associated with diabetes and heart disease (see Harvard Mental Health Letter, December 2000).
In some patients ziprasidone slows electrical conduction through the heart, a phenomenon called QTc prolongation. In this respect it is riskier than the other atypical drugs but less risky than some of the older antipsychotics. A little QTc prolongation is usually harmless, but in severe cases it can lead to irregular heartbeats or sudden death. So far this has not happened to patients taking ziprasidone in clinical experiments. However, the FDA warns against using it in patients with cardiovascular disease or in combination with other medications that may cause QTc prolongation. The FDA does not require physical examinations or heart monitoring, but physicians may choose to perform electrocardiograms on patients at risk for heart disease before prescribing ziprasidone.
Used with permission from Harvard Health Publications.