Co-prescribing of atypical and typical antipsychotics - Prescribing sequence and documented outcome

Abstract

Aims and method: To evaluate patterns of antipsychotic co-prescription and to establish documented outcome, we reviewed 1441 in-patient and community prescriptions written in a large mental health trust. For patients co-prescribed regular atypical and typical antipsychotics for longer than 6 weeks, medication histories were taken and case notes examined to determine sequence of prescribing, documented outcome and reasons for co-prescription. Results: Fifty-three patients had been co-prescribed atypical and typical antipsychotics for more than 6 weeks. In 62% of cases the atypical drug had been prescribed first and a typical drug added later. The most frequently documented reason for co-prescription was that symptoms persisted when prescribed a single antipsychotic. Clinical outcome was documented for 64% of patients: 45% of the total number treated showed some improvement, with seven of 53 patients noted to have shown improvements in psychotic symptoms. Clinical implications: Co-prescription of atypical and typical antipsychotics often occurs as a consequence of poor outcome with single drug treatment. In this study there was minimal evidence to suggest that co-prescription improved outcome to an important extent. There remains little support for co-prescription of antipsychotics but considerable evidence to suggest that such practice worsens adverse effect burden. Co-prescription of atypical and typical antipsychotics should be avoided in all but very exceptional circumstances.