Effect of flurithromycin, a new macrolide antibiotic, on carbamazepine disposition in normal subjects.

The effects of flurithromycin, a new macrolide antibiotic, on the disposition of a single oral dose of carbamazepine (CBZ) (400 mg) were investigated in seven normal subjects. Flurithromycin (2 x 250 mg thrice daily for 10 days) caused a slight increase in the CBZ area under the serum concentration curve and a moderate reduction in carbamazepine-10, 11-epoxide (CBZ-E) levels. These results suggest that flurithromycin can inhibit the conversion of CBZ to CBZ-E, although, at the dosage tested, the magnitude of this effect was significantly smaller than that observed after administration of erythromycin in the same subjects.