%0 Journal Article
%T Commentary on strategies for switching antipsychotics
%A John M Davis
%A Stefan Leucht
%J BMC Medicine
%D 2008
%I BioMed Central
%R 10.1186/1741-7015-6-18
%X Ganguli et al. [1] studied the strategy of switching patients from olanzapine to risperidone. They found that slow tapering of the initial antipsychotic after the new drug had been titrated to the full dose produces fewer problems during the switch than abrupt discontinuation or gradual discontinuation before starting a new drug.The abrupt discontinuation of clozapine does produce an acute worsening of psychosis in some patients and side effects as a result of withdrawal [2]. It is possible that some withdrawal side effects arise from the discontinuation of antipsychotic drugs and/or the antiparkinsonian drugs (often co-administered to reduce extrapyramidal side effects). It is less clear whether this occurs with other antipsychotic drugs [2]. Olanzapine has many pharmacological similarities to clozapine, so it is plausible that such phenomena could occur. Problems that might occur on switching include rebound worsening of psychotic symptoms, side effects, such as the addition of side effects of the old and new drugs, or side effects specific to the new drug, or differences in efficacy between the drugs. Problems might be specific to the discontinuation of the drug or to the drug to which the patient is switched. This strategy (sometimes called 'overlap and taper') ensures that the patient is covered with an adequate plasma level of the added drug before the former drug is discontinued. An increase in side effects did not occur in the Ganguli et al. study [1] or in other studies [3-8]. Such a strategy would not apply to all drugs where the side effects of each of the drugs could combine to produce a significant increase in side effects.Knowing the tactics of switching advances the practical use of these drugs and advances the field. We have good basic information on efficacy, safety and pharmacokinetics from registrational studies. However, there is little information on many of the practical and strategic issues of drug administration [9]. Ganguli et al.'s study is
%U http://www.biomedcentral.com/1741-7015/6/18