Polypharmacy and Potentially Inappropriate Medication Use is Highly Prevalent in Multiple Myeloma Patients and is Improved by a Collaborative Physician-pharmacist Clinic

Objective: To compare polypharmacy and potentially inappropriate medication use in multiple myeloma patients receiving care under a traditional, physician-managed, or collaborative physician-pharmacist clinic.

Design: Retrospective chart review.

Setting: Urban academic cancer center.

Data Source: Computerized electronic record.

Patients: Forty-four patients in the traditional physician-managed clinic and 57 patients in the collaborative physician-pharmacist clinic.

Measurements And Main Results: Patients in the collaborative clinic took fewer medications on average (9 vs. 7,  = 0.045). Although the median number of myeloma-related medications was higher (2 vs. 4,  < 0.0001), the number of non-myeloma-related medications was lower (7 vs. 3,  < 0.0001) in the collaborative clinic. Polypharmacy rates were high in both clinics (93% vs. 84%,  = 0.22). However, the collaborative clinic had a lower rate of polypharmacy of non-myeloma medications (71 vs. 33%,  = 0.0003), including both minor (five to nine medications, 48 vs. 28%,  = 0.06) and major (≥10 medications, 23 vs. 5%,  = 0.02) polypharmacy. Minor polypharmacy of myeloma-related medications was higher in the collaborative clinic (32 vs. 2%;  = 0.0002). Multivariate analysis showed a reduced risk of having a higher number of medications (Relative risk (RR) 0.79, 95% confidence interval 0.67-0.93;  = 0.004), a lower risk of having any polypharmacy of non-myeloma-related medications (RR 0.41, 95% confidence interval 0.25-0.67;  < 0.001) and a lower risk of receiving potentially inappropriate medication (RR 0.62, 95% confidence interval 0.41-0.95;  = 0.029) in the collaborative clinic.

Conclusions: Multiple myeloma patients have a high rate of polypharmacy but comanagement with a pharmacist reduced the number of all medications, but in particular the number of non-myeloma-related medications.