Schizophrenia

In recent years, researchers have developed several new antipsychotic drugs that can be given to schizophrenia sufferers who experience severe side effects from or who do not respond to neuroleptic medications. These new medications are called atypical antipsychotics because they work in a different way from, and have a different effect than, traditional neuroleptics. Scientists are not yet completely sure how these medications work, but the substances seem to affect the action of other neurotransmitters in the brain in addition to dopamine.

The most effective and widely used atypical antipsychotic drug is called clozapine. Clozapine has been found to work for nearly 85 percent of patients with schizophrenia. Unlike traditional neuroleptics, it helps to relieve negative symptoms in addition to positive symptoms. Also, clozapine appears to cause fewer extrapyramidal side effects than do the older antipsychotic medications, and there have been few, if any, cases of tardive dyskinesia that have resulted from clozapine use.

Unfortunately, clozapine can have a serious side effect of its own. People who use this drug have a 1 to 2 percent risk of developing a condition called agranulocytosis. This condition can be life-threatening because it causes a drop in the number of white blood cells in the body. A loss of white blood cells is dangerous because they are the body's main line of defense for fighting infections. Therefore, people who take clozapine have to monitor their white blood cell count each week. If a blood test reveals a drop in the number of white blood cells, use of clozapine is immediately stopped.

There are other atypical antipsychotic medications that have been recently developed, such as risperidone and olanzapine, that do not cause agranulocytosis.