An unexpected increase in deaths was observed among patients with coronary heart disease who received a two-week course of clarithromycin, which first became apparent after one year of follow up. The FDA issued a previous communication regarding this in 2005, but no specific changes to the use of clarithromycin were recommended at the time.
The FDA says the results of this study provide the strongest evidence for an increased risk, which has also been observed in some (but not all) observational studies. They were unable to determine why the risk of death is greater for patients with heart disease.
The current UK SPC for Klaricid does not include any warning of an increased risk of death in patients with heart disease, although caution is advised in various patient groups due to the possibility of prolongation of the QT interval. There is currently no information available as to whether the UK prescribing information for clarithromycin products will be amended to reflect these new findings.