The polypill: An effective approach to increasing adherence and reducing cardiovascular event risk.

Background Despite a wide range of medications being available for the prevention of cardiovascular events such as stroke, myocardial infarction and mortality in both a primary and secondary setting, patient adherence to complex therapy regimens involving different drug classes remains low worldwide. Combining antiplatelet, antihypertensive, lipid-lowering and potentially further drugs into one 'polypill' has the potential to increase adherence, thereby reducing risk factors to a greater extent and for a longer duration. The World Health Organization has recently highlighted increased adherence as a key development need for reducing cardiovascular disease. Methods Recent clinical trial data regarding adherence, reductions in cardiovascular risk and outcomes, safety and tolerability and the cost-effectiveness of the polypill approach are summarised and reviewed. In addition, ongoing trials and the questions they intend to answer are considered. References were retrieved from a PubMed literature search (date range 1990-2016) using the terms 'polypill', 'cardiovascular events' and 'adherence', and selected based on relevance. The website www.clinicaltrials.gov was also consulted for the identification of ongoing trials. Conclusions To date, the polypill approach has been conclusively shown to increase adherence relative to usual care in all patients, with those in a primary care setting or with poor baseline adherence potentially standing to benefit most. Concomitant risk factor reductions have also been suggested. However, whether this translates into a reduction in cardiovascular events and generates good cost-effectiveness in a given healthcare environment is currently under further investigation.