A recent report in the New England Journal of Medicine, as reported in the General Dentistry (Vol.61, #2, p8) indicated there was a small potential increase in the risk of cardiovascular abnormalities resulting in death from certain antibiotics.. These antibiotics are know to cause an increase in the QT interval of the heartbeat; this can cause cardiac problems and even death. Of concern are ERYTHROMYCIN, CLARITHROMYCIN, AZITHROMYCIN and LEVOFLOXACIN. The study reported 29 deaths in a 14 year period involving million of prescriptions. The risk of using these antibiotics, therefore, is extremely low. It is unknown at present whether the vasoconstictor in dental anesthetics has an adverse effect in such patients with prolonged QT intervals, so caution is advised.