In a drug safety communication, the US FDA has advised caution before prescribing the antibiotic clarithromycin (Biaxin) to patients with heart disease because of a potential increased risk of heart problems or death that can occur years later. It also advises prescribers to consider using other antibiotics in such patients. This advisory follows the CLARICOR trial, which found an unexpected increase in deaths among patients with coronary heart disease who received a two-week course of clarithromycin that became apparent after patients had been followed for one year or longer.