Adverse drug reactions in the era of multi-morbidity and polypharmacy

Dear Sir, We read with great interest the article by Sam et al.[1] on the incidence and types of adverse drug events (ADEs) at a major academic medical center. We congratulate the authors for their very timely and valuable contribution to the area of patient safety. Medication errors are becoming more common in the era of increasingly prevalent multi‐morbidity and polypharmacy as the overall age of the global population increases in a demographic megatrend never before seen by humanity.[2‐4] As Sam et al.[1] pointed out, medication errors constitute a significant proportion of healthcare‐associated adverse events. Although the authors categorize ADEs by primary disorder, type of occurrence, and frequency of IHI triggers, they do not provide specific causative risk factors behind the corresponding ADEs.[1] The authors do, however, go on to discuss specific risk factors for drug‐related adverse events, as compiled from various literature sources. Among many factors, they cite patient age, cardiovascular disease, low patient compliance, and polypharmacy as potential contributors.[1] Polypharmacy by itself may play an important role as a risk factor for ADEs, as pointed out by the authors, due to altered pharmacokinetics, pharmacodynamics, and potential drug‐drug interactions among the most frail and thus most susceptible patients.[1,3]