Critical review of antipsychotic polypharmacy in the treatment of schizophrenia

Antipsychotic polypharmacy remains prevalent; it has probably increased for the treatment of schizophrenia in real-world clinical settings. The current evidence suggests some clinical benefits of antipsychotic polypharmacy, such as better symptom control with clozapine plus another antipsychotic, and a reversal of metabolic side-effects with a concomitant use of aripiprazole. On the other hand, the interpretation of findings in the literature should be made conservatively in light of the paucity of good studies and potentially serious side-effects. Also, although the available data are still limited, two smaller-scale clinical trials provide preliminary evidence that converting antipsychotic polypharmacy to monotherapy could be a valid and reasonable treatment option. Several studies have explored strategies to change physicians' antipsychotic polypharmacy prescribing behaviours. These have revealed that, while the impact of purely educational interventions may be limited, more aggressive procedures such as directly notifying physicians by letters or phone calls can be more effective in reducing antipsychotic polypharmacy. In conclusion, antipsychotic polypharmacy can work for some clinically difficult conditions; however, it should be the exception rather than the rule and may be avoidable in many patients. More importantly, the paucity of the data clearly emphasizes the need for further investigations on not only advantages and disadvantages of antipsychotic polypharmacy, but also regarding effective interventions in already prescribed polypharmacy regimens.