Abstract
OBJECTIVE: Although common in psychiatric practice, reasons for antipsychotic polypharmacy (APP) have remained unclear. METHODS: Single-site, semi-structured interview study of prescribers at a psychiatric teaching hospital inquiring about APP attitudes and behaviors, including frequency, preferred combinations, rationale and concerns. RESULTS: Forty-four prescribers reported using APP in 17.0 ± 10.0% of antipsychotic-treated patients. Although clinicians themselves initiated APP in only 23.3 ± 27.0% of cases, they did not attempt conversion to antipsychotic monotherapy in 40.9 ± 37.7%, despite reported successful conversion in 28.0 ± 30.8% of cases. The following reasons justified most APP (0-10): cross-titration (9.2 ± 1.4), failed clozapine trial (8.2 ± 2.2), randomized controlled evidence (8.0 ± 2.0), and clozapine intolerance (7.7 ± 2.6). Prescribers felt "moderately" (5.0 ± 1.9) concerned about APP (0-10), mostly due to chronic side effects (7.6 ± 2.0), lack of evidence (7.1 ± 2.2), non-adherence risk (6.7 ± 2.3) and mortality risk (6.7 ± 3.2), while increased cost (4.9 ± 2.5) and higher total antipsychotic dose (4.2 ± 2.9) ranked lowest. Comparing high with low APP prescribers (>10% vs. ≤ 10% of patients; mean: 36.1 ± 19.8 vs. 3.4 ± 3.4, p<0.0001), no differences emerged on 25/26 ratings regarding APP justification and 9/9 ratings regarding concerns. In a multivariate analyses, only attending status (OR=10.3, p=0.0043) and endorsing a specific APP preference (OR=21.4, p=0.011) predicted APP use >10% (r(2):0.35, p<0.0001), yet no uniformly preferred APP strategy emerged. CONCLUSIONS: High APP prescribers had more clinical experience, less concerns about APP and more likely a preferred APP choice, although no overall preferred strategy emerged. Otherwise, high and low APP prescribers shared attitudes toward APP. Both had inherited most of their APP cases and were reluctant to convert patients to antipsychotic monotherapy.