In our Forum discussion "journal club" series, the editors of Schizophrenia Bulletin provide access to the full text of a recent article. A short introduction by a journal editor gets us started, and then it's up to our readers to share their ideas and insights, questions, and reactions to the selected paper. So read on".
Send in your comments now! The paper under discussion: Remington G, Kapur S. Antipsychotic Dosing: How Much but also How Often? Schizophr Bull. 2010 Sep 1;36(5):900-3. Abstract
Background Text By Gunvant Thaker, Professor and Chief, Schizophrenia Related Disorders Program, Maryland Psychiatric Research Center and Deputy Editor, Schizophrenia Bulletin
In the September 2010 issue of Schizophrenia Bulletin, Remington and Kapur review preclinical and clinical literature on the effects of continuous versus intermittent antipsychotic drug treatment. This review paper draws interesting and provocative conclusions that challenge the established clinical lore regarding the optimal dosing of antipsychotic drugs. The authors point out that while a certain amount of D2 occupancy is critical for the antipsychotic response, continuous high occupancy is not needed. This would suggest that non-continuous antipsychotic dosing would be as effective as continuous dosing, and data from targeted antipsychotic treatment and drug holiday treatment trials support this approach.
Any treatment strategy that reduces total exposure to drugs has advantages and likely reduces side effects. However, does continuous treatment do more harm by modulating the responsivity to the treatment following extended use? This seems unlikely, although a thought-provoking question. The paper also challenges the benefit of extended release formulations. It is somewhat surprising that after half a century of antipsychotic medications, some of the fundamental questions such as frequency of dosing remain. As suggested by the authors, the field needs to focus on several questions in this context. What are effective alternatives to continuous antipsychotic drug treatment? Is the shift toward slow-release formulations wrong-headed? Should one invest in compounds with short half-lives?