Positive impact of clinical pharmacist interventions on antipsychotic use in patients on excessive polypharmacy evidenced in a retrospective cohort study

Abstract

Abstract Objectives Although antipsychotic prescribing in elderly patients using polypharmacy has not been studied in well-designed clinical trials and meta-analyses, there is an urgent need to monitor prescribing practice in this population. One of the possible approaches to optimize pharmacotherapy may be the involvement of clinical pharmacists (CPs). The aim of this research was to examine whether the involvement of a CP can improve treatment guidelines adherence and change the total number of medications per patient in older patients who are treated with excessive polypharmacy that includes antipsychotics. Methods This cohort retrospective study included older patients (65 years or older) treated with at least one antipsychotic and excessive polypharmacy (10 or more medications concurrently) between 2012 and 2014 in primary care. The main outcome measures were antipsychotic treatment guidelines’ adherence and the total number of medications per patient after the CP’s interventions. Only interventions including antipsychotics were studied in detail (i.e., discontinuation, switching, initiation, dose adjustment, change of another medication because of a drug-related problem). Data on diagnoses, patient pharmacotherapy and the CP’s interventions were obtained from clinical records and medical reviews. Age and acceptance of the CP’s interventions were used as predictive factors for antipsychotic treatment guidelines’ adherence. Results Forty-nine patients were included. The CP suggested 21 different interventions of which nine (42.8%) were accepted by the general practitioners. The number of medications that patients received decreased after the CP’s interventions (N of medications before: 15.4; N of medications after: 12.0, p < 0.05). The acceptance of the CP’s recommendations, but not age, improved antipsychotic treatment guidelines’ adherence (p = 0.041). Conclusions These results show that a collaborative care approach including a CP in primary care significantly improved the adherence to treatment guidelines. The results also support the implementation of this service in the Slovenian healthcare system, although more studies are needed.