What is Risperdal?

Risperdal, or risperidone, is the newest medication for treating schizophrenia and psychotic disorders. It helps manage schizophrenia's "positive symptoms" such as visual and auditory hallucinations, delusions, and thought disturbances. Risperdal may also help in treating so-called "negative symptoms" such as social withdrawal, apathy, lack of motivation, and inability to experience pleasure. Side effects are usually relatively minor, and blood monitoring is not necessary. Risperdal is the first new front-line treatment option in twenty years.

How is Risperdal different from other antipsychotic medications?

Conventional antipsychotics such as Haldol, Stelazine, and Prolixin have treated positive symptoms in many patients for several years. However, they do not satisfactorily affect the negative symptoms, and they often cause uncomfortable or intolerable side effects. Risperdal is as effective as the conventional medications in treating positive symptoms. It also offers the advantages of helping to treat some of the negative symptoms somewhat and causing fewer extrapyramidal side effects (EPS) such as restlessness, muscle rigidity, and tremor when taken at the manufacturer's recommended dose of 6 mg per day.

Why is Risperdal called a new "front-line option?"

It means that Risperdal could be the first medication prescribed for a person who is newly diagnosed with a psychotic disorder. Some medications, such as clozapine, have side effects that may be inconvenient or difficult to manage. Such medications may be reserved until after other medications have been tried unsuccessfully. Because Risperdal is effective and has relatively few side effects, doctors may consider it one of the first medications to try for patients with schizophrenia. It's important to remember that no medication will work for everyone, and some patients will have greater success with Risperdal than others.

How does Risperdal work?

Risperdal, like other new antipsychotic drugs currently under development, is designed as a serotonin/dopamine antagonist. While its exact mechanism of action is not yet understood, Risperdal seems to block the action of serotonin and dopamine, two neurotransmitter chemicals in the brain. Conventional antipsychotics seem to primarily affect only dopamine.

How quickly does Risperdal relieve symptoms of schizophrenia?

The recommended dose is usually reached within three to four weeks, and improvement of symptoms may be noticed in some patients relatively quickly. Some adjustments may be necessary to reach the optimal dose for each patient. It is normally advisable to give the medication a trial period of at least four to six weeks at the optimal dose (6 mg/day) before evaluating its effectiveness, although experience with clozapine suggests that improvements may take months to fully emerge.

What are the side effects of Risperdal?

When taken at the manufacturer's recommended dose of 6 mg a day (3 mg twice a day), the incidence of many side effects is not significantly greater than for placebo. These side effects include extrapyramidal symptoms (muscle stiffness, tremors, and body shakes). At higher doses, extrapyramidal side effects often increase. Benztropine (Cogentin) can be prescribed to reduce or eliminate stiffness and tremors, but its use beyond three months should be re-evaluated.

More significant possible side effects, affecting some patients but not all, include low blood pressure, dizziness, especially when standing up suddenly; heart palpitations; sleepiness; constipation; weight gain; sexual dysfunction; and fatigue. Some of these problems can be minimized by following recommended guidelines for dosage at the beginning of treatment (gradual increase of dose over a period of several weeks). Patients who already have low blood pressure, who have kidney or liver impairment, are elderly, or in a weakened condition may require close monitoring and even more gradual dose adjustment.

Does Risperdal cause tardive dyskinesia?

Tardive dyskinesia (TD), a disfiguring side effect that occurs in some patients taking antipsychotic drugs, may not be a major risk associated with Risperdal use, although it may take years before researchers can fully assess the risk. It is prudent to minimize the risk by using the lowest dose necessary to relive psychotic symptoms. Should symptoms of TD develop, such as grimacing, sucking and smacking of lips and other spasmodic movements, discontinuation of Risperdal should be considered.

What else should be kept in mind when taking Risperdal?

Risperdal is usually taken twice a day. It can be take before, during, or after meals. Because of its long half-life (similar to haloperidol), however, once daily dosing should be considered. Patients should be cautious about operating hazardous machinery, including driving, until they are certain they are not adversely affected. Women should let their doctor know if they become pregnant or intend to become pregnant. Breast feeding is not recommended while taking Risperdal. Because some medications can affect the effectiveness of Risperdal when taken at the same time, patients should be sure their doctor is aware of all medications they are taking.

How much does Risperdal cost?

At the recommended dose of 4-6 mg a day, Risperdal is expected to cost the patient less than $3,000 a year. Some insurance policies will cover the cost. Uninsured outpatients who meet income eligibility standards may qualify for low cost or free Risperdal through the manufacturer. Janssen Pharmaceutica also answers questions about insurance coverage, and offers assistance in filing claim forms and resolving claims that have been denied. For information on the Risperdal Patient Assistance Program and the Risperdal Reimbursement Support Program, call 1-800-652-6227.

Reviewed by David Pickar, M.D., Chief, Experimental Therapeutics Branch, National Institute of Health, (5/94) and Dale R. Grothe, Pharm.D., Mental Health Clinical Pharmacy specialist, NIH/NIMH Pharmacy Dept. (12/95)