Clinical issues associated with maintenance treatment of patients with schizophrenia

Issues to consider when evaluating maintenance drug therapy for patients with schizophrenia are discussed; these include potential adverse effects of antipsychotic therapy, such as weight gain, diabetes mellitus, extrapyramidal symptoms, sexual dysfunction, cognitive dysfunction, and cardiac effects, as well as quality of life. Patients with schizophrenia are more likely to be overweight than the general population. Olanzapine and clozapine have been associated with the greatest weight gain of the newer antipsychotics. While patients with schizophrenia are at increased risk of developing diabetes mellitus independent of antipsychotic therapy, diabetes may be more prevalent in patients taking the newer agents. Acute extrapyramidal symptoms occur in 75-90% of patients receiving first-generation antipsychotics like thioridazine and haloperidol. The probability of tardive dyskinesia (TD) occurring with second- and third-generation agents is less than 1% per year, compared with about 5% per year for the traditional antipsychotics. When patients are switched from a traditional antipsychotic to clozapine or olanzapine, TDs usually abate somewhat. Thioridazine causes a pronounced prolongation of the QTc interval, which can lead to ventricular arrhythmias. The slight increase in QTc interval caused by ziprasidone most likely will not be a problem in healthy individuals. Newer antipsychotics are associated with improved neurocognitive functioning and most cause less prolactin elevation, compared with traditional agents. The newer antipsychotic agents are not devoid of adverse effects, but those that do occur can be managed. Once issues related to adherence are resolved, rehabilitation of patients with schizophrenia will be a high priority.