The use of common painkillers appears linked to increased risk of heart attack, according to Canadian researchers, with the risk present after as little as one week of taking the tablets.
The scientists, led by Michèle Bally of the University of Montreal Hospital Research Centre, carried out a meta-analysis of studies tracking painkiller use previously conducted in Canada, Britain and Finland.
All up, the team analysed results for almost 446,700 people, 61,460 of whom had suffered a heart attack.
Under investigation was the use of non-steroidal anti-inflammatory drugs (NSAIDs), including the commonly prescribed diclofenac, ibuprofen and naproxen.
The study looked at these “traditional” NSAIDs as well as more controversial so-called “COX2” versions – one of which, rofecoxib, marketed as Vioxx, was withdrawn from the market in 2004 after being linked with increased heart attacks and strokes.
The association between NSAIDs and heart attack risk was noted some years ago, but until Bally’s team set to work no one had attempted to quantify the relevant onset, the effect or dose, or the comparative risks of various types.
The team’s results, published in The BMJ, indicate that heart-attack risk increased after as little as a week taking the medications. The risk seems to reach a peak after about one month on the painkillers and then plateau thereafter.
Higher doses also correlated with higher risk.
Across the spectrum of NSAIDs, the risk of a heart attack was 20-50% higher compared to not taking the drugs.
Bally and colleagues caution that the findings are derived from observational studies and therefore a direct cause-and-effect relationship cannot be inferred. They note there may be other contributing factors not recorded in the data.
Nevertheless, they add, the apparent correlation between painkiller use and heart-attack risk should be enough to make doctors think twice before prescribing.
“Given that the onset of risk of acute myocardial infarction occurred in the first week and appeared greatest in the first month of treatment with higher doses, prescribers should consider weighing the risks and benefits of NSAIDs before instituting treatment, particularly for higher doses,” they write.