PHARMACOKINETICS AND SAFETY OF DIRITHROMYCIN IN THE ELDERLY

Pharmacokinetic and safety studies were undertaken in elderly (age 65 years) and non-elderly (age 18-50 years) subjects receiving the normal recommended dose of 500 mg/day dirithromycin for ten days. There was a considerable variation in the maximum plasma concentration and time when this was achieved in each of the subject groups. There was also a trend for values for the area under the plasma concentration versus time curve to increase with age, but neither of these pharmacokinetic parameters was significantly altered with age. The incidence and nature of adverse events were similar in elderly and non-elderly subjects, and there was no electrocardiographic evidence that dirithromycin caused an increased incidence of cardiac disturbances. No changes in clinical laboratory values were thought to be due to dirithromycin. It is concluded that 500 mg/day dirithromycin may be used to treat elderly patients without the need for any dose adjustment. © 1993 The British Society for Antimicrobial Chemotherapy.