Polypharmacy in Patients With COPD: A Scoping Review

Chronic obstructive pulmonary disease (COPD) is a global health challenge. Increasing numbers of patients with COPD are prescribed multiple medications (both for COPD and non-COPD disorders). This increases the risk of polypharmacy in these patients which can be linked with patient harm. However, the definition of polypharmacy is varied across literature (ranging from use of ≥3 to ≥20 medications). This review aims to report the prevalence of polypharmacy, report the varying definitions of polypharmacy, and report medication related harms amongst patients with COPD. We identified 28 studies reporting polypharmacy rates in COPD populations. A total of 13 studies (46.3%) defined polypharmacy as the use of ≥5 medications; however, the remaining studies had different definitions of polypharmacy. The available studies include multiple different countries and settings (primary care, secondary care, and community-based surveys). Polypharmacy and hyper polypharmacy (use of ≥10 medications) rates varied from 3.9% to 81.4% and 6.6% to 74.6% respectively. Polypharmacy in patients with COPD is common but poorly understood due to difficulty in comparing previous literature with differences in methodologies, patient populations, and definitions of polypharmacy. The multimorbid COPD population is likely at higher risk to the effects of polypharmacy through poor adherence, adverse drug reactions, and drug-drug interactions. Clinicians should be mindful of the patient's age, comorbidities, and drug-drug interactions while prescribing medications in the COPD clinic.