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Schizophrenia drug approved but with a name change

Pfizer Inc.'s new schizophrenia therapy got the Food & Drug Administration's go-ahead earlier this month, but federal regulators nixed the drug's proposed brand name and raised a caution flag about potential heart risks.

Ziprasidone HCl is a novel antipsychotic drug for the treatment of schizophrenia. It is a serotonin and dopamine antagonist indicated for treating the positive and negative symptoms associated with the condition, including visual and auditory hallucinations, delusions, lack of motivation, and social withdrawal.

Although the FDA found ziprasidone to be effective, the agency issued a warning that the drug may cause long QT interval, which raises the possibility of dangerous irregular heartbeats and sudden death. The agency, however, did not require a black box warning or that patients undergo electrocardiograms at initiation of therapy or during the course of treatment. The decision of whether to prescribe ziprasidone or another antipsychotic agent as first-line therapy was left to the physician's best professional judgment.

Pfizer had sought to market the new drug under the brand name Zeldox. But the FDA decided that name was too similar to other drugs, such as Zyvox, already on the market, which could lead to medication errors stemming from look-alike or sound-alike drug names. Although the FDA found its alternative name of Geodon acceptable, Pfizer has not officially selected a new name for the drug.

Ziprasidone was the subject of worldwide clinical trials that enrolled 4,500 patients, the largest ever conducted for an antipsychotic medicine prior to introduction, according to Pfizer. In placebo-controlled, short-term clinical trials, ziprasidone 20 mg to 100 mg twice daily was statistically superior to placebo for treatment of schizophrenia and schizoaffective disorder. A one-year, placebo-controlled study in chronic, stable inpatients found that ziprasidone was effective in delaying the time to and rate of relapse.

Unlike some other antipsychotic drugs, ziprasidone is not associated with weight gain, according to Pfizer. Putting on weight due to a medication is distressing for patients and can have a negative impact on compliance. The most common side effects included headache, somnolence, abnormal movements, respiratory disorders, nausea, constipation, and dyspepsia. The side effects were generally mild to moderate and rarely led to discontinuation of the drug.

Pfizer plans to introduce ziprasidone next month in 20-mg, 40-mg, 60-mg, and 80-mg capsules in bottles of 60. The New York City-based firm did not reveal the drug's price.

Carol Ukens

TIPS TO REMEMBER: Ziprasidone

• The initial daily dose of ziprasidone is 20 mg b.i.d. with food. Adjustments should generally occur at intervals of not less than two days. An increase to a dose greater than 80 mg is generally not recommended.

• Because of its dose-related prolongation of the QT interval, ziprasidone should not be used with other drugs that prolong the QT interval.

• Ziprasidone should be avoided in patients with histories of significant cardiovascular illness.

• Patients at risk for significant electrolyte disturbances, especially hypokalemia, should have baseline serum potassium and magnesium measurements. It is essential to periodically monitor serum electrolytes in patients placed on diuretic therapy during ziprasidone treatment.

• Ziprasidone should be used during pregnancy only if the potential benefit justifies any potential risk to the fetus. Also, it's recommended that women should not breastfeed while on ziprasidone therapy.

• It should be ascertained if a patient prescribed ziprasidone is taking other prescription or nonprescription drugs, supplements, or herbals, which may combine to increase the risk of cardiac irregularities.

 

Carol Ukens. Schizophrenia drug approved but with a name change. Drug Topics 2001;4:12.