Multiple antipsychotic medication prescribing patterns.

Objective: To assess current prescribing practices regarding concomitant use of antipsychotic medications and summarize the reasons clinicians may prescribe >1 scheduled agent.

Methods: The pharmacy identified patients at William R Sharpe Jr Hospital currently receiving antipsychotic therapy. All patients receiving >/=2 scheduled antipsychotic agents concomitantly were included in the study. Data regarding the demographics, current medication combinations used, history of therapeutic regimens tried, and prescriber rationale were prospectively evaluated for a 60-day period beginning December 13, 2000, and ending February 10, 2001. Prescriber rationale for using >1 antipsychotic simultaneously and other drug therapy regimens that had been tried were compared with chart documentation and published therapeutic guidelines for schizophrenia.

Results: Over a 60-day surveillance period, 206 patients were placed on scheduled antipsychotic medications, with 85 (41%) receiving at least 2 agents. Responders to a prescriber questionnaire (59%) indicated the most common rationale for combination therapy was augmentation; the least likely rationale was cross-titration. Survey responses also indicated a belief that there was questionable therapeutic benefit in more than half of the patients being treated with multiple antipsychotic combinations. Additionally, chart documentation showed that the majority of these patients did not receive an adequate trial of monotherapy with other atypical or typical agents, or clozapine prior to the combination antipsychotic regimen. Fifty-one percent of medical records did not document the rationale for concomitant therapy.

Conclusions: Due to the lack of published data, the practice of using multiple antipsychotic agents is considered to be a gray area that requires the prescriber to be at a heightened level of awareness in assessing effectiveness and safety. Documentation of rationale, adverse effects, and response to the treatment regimen is essential in providing optimal care for the patient.