Discovered and developed by Pfizer, ziprasidone is a serotonin and dopamine antagonist that is effective across its dose range in treating the positive and negative symptoms associated with schizophrenia. These include visual and auditory hallucinations, delusions, lack of motivation and social withdrawal. The 4,500-patient worldwide clinical trials program for ziprasidone is the largest ever conducted for an antipsychotic medicine prior to introduction.

Despite advances in treatment, physicians and other health care providers continue to face significant challenges in the management of schizophrenia, Pfizer said.

“Schizophrenia is a devastating and debilitating psychiatric disorder, impacting patients, their family members and caregivers,” said John F. Niblack, Ph.D. Vice Chairman and President of Pfizer Global Research and Development. “Ziprasidone is an important new therapeutic option with long-term efficacy and a very favorable side effect profile, including an essentially neutral effect on patients’ weight levels.”

Weight gain, associated with some widely used antipsychotic medicines, is distressing and stigmatizing to patients, and can result in patient non-compliance. Patients who gain weight may also be at greater risk for cardiovascular complications such as increased lipid levels and poor glycemic control. Hence, the weight neutral profile of ziprasidone should prove an important and advantageous feature of the drug.

Schizophrenia is a life-long illness that affects approximately one percent of the world’s population and is estimated to cost more than $104 billion in hospital costs, medications, health care services and lost productivity. Typically, schizophrenia strikes men and women in their late adolescence or early 20s and is chronic, often with multiple relapses and impaired daily functioning.

In placebo-controlled, short-term (4 and 6 week) clinical trials, ziprasidone 20 to 100 mg twice daily was statistically superior to placebo for treatment of positive and negative symptoms in patients with acute exacerbation of schizophrenia and schizoaffective disorder.

In a one-year placebo-controlled study, in chronic, stable inpatients, ziprasidone was shown to be effective in delaying the time to and rate of relapse. Since schizophrenia is typically a lifelong illness that is complicated by high rates of relapse, relapse prevention is an important goal in the management of this illness

The most common side effects exhibited by persons in clinical trials treated with ziprasidone included headache, somnolence, abnormal movements, respiratory disorders, nausea, constipation and dyspepsia. These side effects were generally of mild to moderate severity and rarely led to discontinuation of the drug.

Ziprasidone is also associated with a small prolongation of the QTc interval of the electrocardiogram, an effect seen with certain other marketed medicines, including some anti-psychotics. This effect was well characterized in the extensive ziprasidone clinical trials database and is reflected in the FDA’s product labeling, which suggests that physicians use their best judgement, based on the overall status of the patient, as to whether ziprasidone or another antipsychotic agent be used first.

Pfizer said the product label does not include a black box warning or a requirement that patients receive electrocardiograms either at initiation or during treatment with ziprasidone.

The company said it expects to introduce ziprasidone in the U.S. in 20 mg, 40 mg, 60 mg and 80 mg capsules in March. Pfizer said it is discussing several potential trade names for ziprasidone with the FDA.

Pfizer Inc discovers, develops, manufactures and markets leading prescription medicines, for humans and animals, and many of the world’s best known consumer products. Pfizer had global revenues of $29.6 billion in 2000. Pfizer plans to make a research and development investment of $5 billion in 2001.