Schizophrenia Drug Therapy

Schizophrenia is a severe mental illness which is extremely costly to society. Unlike heart disease and cancer, this illness which afflicts about 1% of the population strikes individuals early in life and has an extremely long course. Individuals with schizophrenia have to take medication for the rest of their life and are often hospitalized for a large portion of adulthood. The long survival and costly care in institutions means that schizophrenics run up huge medical expenses over the 50-60 year course of their illness. Also unlike heart disease and cancer, schizophrenics rarely have a chance to contribute to the society. The end result, when all of these factors are considered, is that schizophrenia's societal cost is almost half that of heart disease, despite the fact that many more people are afflicted with heart disease than schizophrenia.

Recently, a new drug has given hope to schizophrenics. The first major advance in schizophrenia drug therapy in 20 years was the introduction of clozapine in the 1980's. While this drug acts like other antipsychotic drugs in some patients, in others, its effects are nothing short of miraculous. Patients who have been hospitalized for many years have become well enough taking clozapine to return to their homes and their work. The problem with clozapine is the presence of a very serious, life-threatening side effect that cannot be predicted - severe loss of white blood cells. Patients on clozapine must have very expensive white blood cell counts performed every two weeks to catch the problem before it is too late. This new drug has led to the search for other clozapine-like antipsychotics. Using clues about which neurochemical receptors clozapine influences, researchers have designed drugs that may work as well as clozapine. One of these new drugs is iloperidone. We are treating schizophrenics with iloperidone in a trial to find out which dose of the compound is most effective at decreasing the symptoms of schizophrenia without causing the side effects sometimes seen at high doses of neuroleptics (drug-induced parkinsonism, sedation).

Patients at Waco (along with other sites across the country) have their current medication removed for 7 days and then receive one of three doses of iloperidone or a placebo. After a month, all the patients are given a moderate dose of the drug for one year. Symptoms of schizophrenia and side effects are measured every week to determine which dose of iloperidone is best. There is no evidence for clozapine's blood complications with iloperidone, but other long term effects of continued therapy will be determined during the year of treatment. When we have completed the study and all the data is collected from across the country, we will be able to tell which dose of iloperidone has the best benefit/side effect ratio, and whether or not it will be as useful as clozapine.