PARIS: Danish researchers reported a link between a commonly-used antibiotic and a “significantly” higher risk of heart deaths, while observers urged caution in interpreting the results.
In a study published online by the British medical journal The BMJ, the team said clarithromycin use was associated with a 76-percent higher risk of cardiac death, compared to use of penicillin V.
“The absolute risk difference was 37 cardiac deaths per 1 million courses with clarithromycin,” reported the trio from the Statens Serum Institute’s epidemiology department in Copenhagen.
The risk stopped when treatment ended.
Clarithromycin is prescribed to millions of people every year, to treat bacterial infections like pneumonia, bronchitis and some skin infections.
The team had analyzed data from more than five million antibiotics courses given to Danish adults aged 40 to 74 in the period 1997 to 2011.
Of the patients, just over 160,000 had received clarithromycin, 590,000 roxithromycin, and 4.4 million penicillin V.
Clarithromycin and roxithromycin are macrolides —antibiotics that affect the electrical activity of the heart muscle and are thought to increase the risk of fatal heart rhythm problems, the researchers said.
No increase in risk was observed with roxithromycin.
While the absolute increase in risk with clarithromycin was small, the team said, it was “one of the more commonly used antibiotics in many countries . . . thus the total number of excess cardiac deaths may not be negligible.”
The researchers called for their findings to be confirmed in further studies, even as a host of other experts pointed out that the study did not warrant a halt to clarithromycin use.