Telithromycin (HMR 3647) achieves high and sustained concentrations in tonsils of patients undergoing tonsillectomy

Abstract Telithromycin, the first ketolide antimicrobial to be developed for clinical use, has potent activity against group A β-haemolytic streptococci (GABHS), including macrolide-resistant strains. The penetration of telithromycin into tonsils was assessed in 22 adults undergoing tonsillectomy at 3, 12 or 24 h after the fourth dose of oral telithromycin 800 mg once daily. Telithromycin rapidly penetrated tonsillar tissues, achieving a mean concentration of 3.95 mg/kg at 3 h post dose, 3.4 times greater than the corresponding plasma concentration (1.22 mg/l. The mean tonsil:plasma concentration ratio increased to 13.1 at 24 h post dose, indicating slower elimination from tonsils than plasma. Tonsillar and plasma concentrations exceeded the MIC 50 for GABHS throughout the 24-h dosing period. These findings suggest that telithromycin may be an effective new alternative treatment for GABHS tonsillopharyngitis.