A study in this week's PLOS Medicine finds that the painkiller diclofenac (a non-steroidal anti-inflammatory drug (NSAID) in the same class as aspirin) is the most commonly used NSAID in the 15 countries studied and is included in the essential medicines lists of 74 low-, middle- and high-income countries, despite its known tendency to cause heart attacks and strokes in vulnerable patients. This risk is almost identical to that of Vioxx (rofecoxib), which was withdrawn from worldwide sales in 2004 because of cardiovascular risk. Researchers writing in this week's PLOS Medicine call for diclofenac to be removed from national essential medicines lists and to have its global marketing authorisations revoked.

It has been known for over a decade that some NSAIDs such as diclofenac are associated with more cardiovascular complications than other NSAIDs such as naproxen, but in an analysis of the essential medicines lists of 100 countries, Patricia McGettigan from Barts and The London School of Medicine and Dentistry and David Henry from the Institute for Clinical Evaluative Sciences and the University of Toronto, Canada, found that diclofenac was listed in the essential medicines lists of 74 countries and naproxen, a much safer alternative, in just 27.

Furthermore, in an in-depth analysis of the sales and prescriptions of NSAIDs in a selection of 15 low-, middle-, and high-income countries using information from 2011, they found that diclofenac sales (or prescribing, in the case of England and Canada) were three times higher than that of naproxen. The findings demonstrate that evidence about the risks associated with diclofenac has translated poorly to clinical practice.

McGettigan states: "Diclofenac has no advantage in terms of gastrointestinal safety and it has a clear cardiovascular disadvantage." Henry added: "Given the availability of safer alternatives, diclofenac should be de-listed from national essential medicines lists. McGettigan concludes: "There are strong arguments to revoke its marketing authorisations globally."

In an accompanying Perspective, K. Srinath Reddy from the Public Health Foundation of India and Ambuj Roy from the All India Institute of Medical Sciences (uninvolved in the study) say that the results of this study suggest that immediate action is warranted to remove diclofenac from national drug lists and that the World Health Organization should provide information on the safety of NSAIDs.

However, according to Reddy and Roy, it is not just the case of diclofenac versus naproxen that is at stake but the broader challenge of ensuring that everyone responsible for the safety of patients makes informed decisions in an appropriate and timely manner.

Reddy and Roy conclude: "If we do not collectively rise to that challenge, no NSAID can relieve the pain of that failure."

McGettigan P, Henry D (2013) Use of Non-Steroidal Anti-Inflammatory Drugs That Elevate Cardiovascular Risk: An Examination of Sales and Essential Medicines Lists in Low-, Middle-, and High-Income Countries. PLoS Med 10(2): e1001388. doi:10.1371/journal.pmed.1001388