Strategies for Early Non-response to Antipsychotic Drugs in the Treatment of Acute-phase Schizophrenia

Hatta, Kotaro; Ito, Hiroto

Abstract

As a strategy for antipsychotic treatment of schizophrenia, monotherapy is clearly optimal when both effective and tolerated. When a patient fails to respond to an adequate dose of an antipsychotic, alternatives include switching, administering a higher dose (above the licensed dose), polypharmacy or clozapine. Clozapine is the only option with established efficacy, but is less manageable than other antipsychotics. We therefore reviewed other options, focusing on the treatment of acute-phase schizophrenia. According to recent evidence, an antipsychotic may be viewed as ineffective within 1-4 weeks in acute-phase practice, although some differences may exist among antipsychotics. Whether a switching strategy is effective might depend on the initial antipsychotic and which antipsychotic is switched to. As weak evidence points toward augmentation being superior to continuation of the initial antipsychotic, inclusion of augmentation arms in larger studies comparing strategies for early non-responders in the acute-phase is justified. With respect to high-doses, little evidence is available regarding acute-phase treatment, and the issue remains controversial. Although evidence for antipsychotic switching, augmentation, and high-doses has gradually been accumulating, more studies performed in real clinical practice with minimal bias are required to establish strategies for early non-response to an antipsychotic drug in the treatment of acute-phase schizophrenia.