Diclofenac & Other Common Painkillers Raise Heart Attack Risk By Up To 40%

A study, published earlier this week in the journal PLoS Medicine, has raised concerns about the safety of some common painkillers after finding the use of some common drugs including naproxen, ibuprofen, celecoxib, and diclofenac, raise the risk of suffering a heart attack by as much as 40%.

The research, conducted by Patricia McGettigan of the Hull York Medical School in the UK and David Henry of the Institute for Clinical Evaluative Sciences in Canada, involved analysing the results of 51 previous studies involving more than 2.7 million individuals, to establish the effects of painkillers on the risk of myocardial infarction.

The researchers found increased heart attack risks for all the drugs studied. Of the most commonly used painkillers, diclofenac (which is sold under the brand names Voltaren and Cataflam), was found to be the most dangerous with a 40% increased risk of heart attacks. Ibuprofen (brand names: Advil and Nurofen), increased heart attack risk by 18%, celecoxib (brand names: Celebrex and Celebra) increased risk by 17%, while naproxen (brand names: Naprosyn, Aleve, Anaprox and Naprelan) increased risk by 9%.

Interestingly, rofecoxib was found to increase heart attack risk by 45% which is only marginally higher than the risk to diclofenac users. Rofecoxib was voluntarily withdrawn by the manufacturer, Merck & Co. in 2004 after concerns were raised about the risks of heart attacks and other cardiovascular events, a move that cost the company more than $2 billion a year in sales.

The researchers also grouped the data by dosage. Ibuprofen and naproxen in low doses (less than 1200-1800 mg/day and 500-1000 mg per day respectively), did not increase the risk of heart attacks by a statistically significant amount however low dose diclofenac (less than 100-150 mg/day) was still associated with a 22% increased risk. These results are important because these three drugs are available in low doses over-the-counter in many countries.

Among the less common painkillers studied, indomethacin increased risk by 30%, piroxicam by 8%, meloxicam by 20%, etodolac by 55%, and valdecoxib by 5%. Etoricoxib was associated with a greater risk of heart attack than any other drug studied, raising risk by a massive 105% although the results for the drug were limited to 4 relatively small studies. Etoricoxib is not currently approved for use in the USA although it is available in more than 70 countries including India, and much of Europe and Latin America.

Among the common painkillers not included in this study, paracetamol (or acetaminophen) has not been linked to an increased risk of heart attack in any scientific studies however exceeding the recommended dose carries a relatively significant risk of liver damage. Aspirin on the other hand actually reduces the risk of myocardial infarction by between 10 and 20% at low doses of between 70 and 150 mg per day. Aspirin does not appear to be linked to an increased risk of heart attack at higher doses although is almost never prescribed because it is considered to carry an unacceptably high risk of gastric bleeding.

Pressure must surely now go on the manufacturer and the FDA to limit the availability of diclofenac. On the basis of this study, diclofenac should, at the very least, be withdrawn from over the counter use and prescribed only to individuals with a very low base risk of myocardial infarction.