The influence of polypharmacy, potentially inappropriate medications, and drug interactions on treatment completion and prognosis in older patients with ovarian cancer

Background: Older patients with cancer are at increased risk of exposure to polypharmacy (PP), potential drug interactions (PDIs), and Potentially inappropriate Medications (PIMs). Objectives of this study were to describe PP, PIMs, and PDIs, and to analyse the associations with completion of 1st line chemotherapy and prognosis in ovarian cancer (OC) patients.

Methods: Registry-based study including a 10-year national cohort of patients diagnosed with epithelial OC in Denmark. Descriptive statistics, multivariate logistic regression analyses, Kaplan-Meier, and Cox regression analyses were performed to analyse the data.

Results: A total of 3795 patients were included and described. Further analyses were performed on 2219 patients registered with a date of surgery and combination chemotherapy with platinum and a taxane or platinum monotherapy. Exposure to ≥2 PDIs was associated with not completing chemotherapy, odds ratio (OR) 2.27 (1.18-4.37). Major and extensive PP were associated with increased mortality at 0-6 months after diagnosis, HR 3.15(1.59-6.22) and 5.43(2.34-12.6), respectively. PIMs were associated with increased mortality from six months after diagnosis. At 6-12 months: hazard ratio (HR) 1.50(1.06-2.11) and 2.38(1.25-4.50) with 1-2 and ≥ 3 PIMs, respectively. At 12 months: HR 2.08(1.31-3.29) with ≥3 PIMs. Age was not associated with treatment completion.

Conclusions: Drug use influences treatment completion and prognosis in OC patients. A thorough review of patients' medications aiming to minimize the number of PIMs and PDIs might improve the course of these patients' disease.