Clinicians' reasons for antipsychotic coprescribing.

Background: Prescribing more than 1 antipsychotic is common but has received little supportive evidence in the literature. This study was designed to systematically survey clinicians about their rationale for prescribing more than 1 antipsychotic for specific patients.

Method: Patients with schizophrenia (diagnosed according to ICD-9 criteria from October 1, 1999, to September 30, 2000) at 2 Veterans Administration (VA) medical centers and their prescriptions for anti-psychotics (filled within the VA system from June 1, 2000, through September 30, 2000) were identified from administrative databases. Clinicians for each patient with more than 1 antipsychotic prescription were interviewed using a structured questionnaire. After summarizing offered explanations, we compared patients prescribed 2 atypicals with those prescribed an atypical and a conventional.

Results: The treatment of 66 patients was reviewed. The 4 most common reasons for coprescription were reducing positive symptoms (61%), reducing negative symptoms (20%), decreasing total amount of medication (9%), and reducing extrapyramidal symptoms (5%). In 65% of patients (41/63), psychiatric symptoms were thought to have been refractory to antipsychotic monotherapy. In 39% of patients (N = 26), antipsychotic coprescription was intended to be transitional, but in only 46% of these patients (N = 12) had this transition been completed after 6 to 12 months.

Conclusion: Prescribers for patients receiving more than one antipsychotic were frequently able to cite plausible and specific target symptoms they were attempting to address with this practice.