The FDA ( U.S. Food and Drug Administration ) alerted the public to a study showing a higher death rate among patients in Denmark with heart disease a year after taking Clarithromycin, an antibiotic.

The CLARICOR study reported increased mortality in patients treated with Clarithromycin ( Biaxin/Klacid ) for 14 days compared with patients who received a placebo.

The difference in mortality became apparent after patients had been followed for one year or longer after the study drug was given.

A mechanism by which two-weeks of Clarithromycin could cause increased mortality measured after one year or longer is not clear.

Previous trials of antibacterial drugs to prevent heart disease and other trials of Clarithromycin have not shown a statistically significant effect on mortality.

Considering the results from the CLARICOR study and the results from previous studies of antibacterial drugs to prevent heart disease, the FDA is not recommending any specific changes to the use of Clarithromycin at this time.

FDA has discussed these findings with the Danish Medicines Agency ( DMA ) and the FDA recommendation is consistent with that of the DMA.

The purpose of CLARICOR study was to determine if the macrolide Clarithromycin affects mortality and cardiovascular morbidity in patients with stable coronary heart disease.

A total of 4373 patients aged 18 to 85 years who had a discharge diagnosis of myocardial infarction or angina pectoris in 1993-9 and alive in August 1999 were randomised to two weeks' treatment with Clarithromycin 500 mg/day or placebo.

Primary outcome was: composite of all cause mortality, myocardial infarction, or unstable angina pectoris during three years' follow-up.
Secondary outcome was: composite of cardiovascular mortality, myocardial infarction, or unstable angina pectoris.

Researchers found no significant effects of Clarithromycin on the primary outcome ( hazard ratio, HR=1.15 ) or secondary outcome ( HR=1.17 ).
Mortality was significantly higher in the Clarithromycin arm ( HR=1.27; P=0.03 ) as a result of significantly higher cardiovascular mortality ( HR=1.45; P=0.01 ).

“ Short term Clarithromycin in patients with stable coronary heart disease may cause significantly higher cardiovascular mortality. The long term safety of Clarithromycin in patients with stable ischaemic heart disease should be examined, “ the authors concluded.

Source:

1) British Medical Journal, 2005

2) FDA, 2005


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