The impact of climate change on human health and pharmaceuticals

Climate change and air pollution affect every major organ system, altering both the disease burden and patient responses to pharmaceutical treatments. However, current knowledge on how health systems, patients, healthcare professionals, and governments should prepare for these challenges remains fragmented. This review synthesises evidence on the potential impact of climate change on human health and pharmaceuticals, with the aim of identifying the diseases, populations, and medications most vulnerable, and assessing potential implications for pharmacotherapy. Emerging evidence shows that climate-related stressors, particularly extreme heat, contribute to increased morbidity and mortality and exacerbation of diseases affecting cardiovascular, cerebrovascular, gastrointestinal, renal, and respiratory systems. Furthermore, the review found that high temperature and humidity can affect drug stability, bioavailability, and pharmacokinetics by degrading active pharmaceutical ingredients and altering pharmaceutical formulations, potentially reducing efficacy and increasing the risk of adverse drug events. Older adults, patients with chronic diseases, and those taking medications that impair the thermoregulatory system are particularly at higher risk. In addition, extreme weather events may also disrupt pharmaceutical supply chains, further threatening access to essential medicines. This review finds that climate change has implications for healthcare through increasing disease burden and affecting the effectiveness and safety of medicines. Therefore, there is an urgent need for integrated research to explore the interplay between climate change, therapeutic response, and drug safety to support resilient, climate‑ready healthcare systems.