Copyright 2002 American Medical Association. All Rights Reserved.
Applicable FARS/DFARS Restrictions Apply to Government Use.2002
Purdon et al1 have presented, with
many qualifications, results from a double-blind randomized trial comparing
the cognitive benefits of olanzapine, risperidone, and haloperidol. Studies
of this type are important; however, the interpretation of the referenced
study requires caution, and the clinical relevance of the data is limited.
In disclosing the increasing interest in slower titration and lower
doses of risperidone than were used in the trial, the authors assert that
the dosing schema they used was valid because it was consistent with the relevant
product monograph and with the doses used in an earlier study.2
Emerging data and clinical practice often lead advances in the standard of
care, and changes to product literature lag behind. Also, the study that was
cited for setting a dosing precedent was conducted in a refractory population
that can be expected to require higher medication doses. A more credible discussion
of the aberrantly high doses of risperidone used in the trial would be made
by using audited pharmacy data to get a realistic assessment of the average
daily doses used in practice at the participating centers.
Sharma T. Atypical Antipsychotics and Cognition in Schizophrenia. Arch Gen Psychiatry. 2002;59(6):571-572. doi: