Clarithromycin has a fairly rapid first-pass metabolism in the liver. Its major metabolites include an inactive metabolite, N-desmethylclarithromycin, and an active metabolite, . Compared to clarithromycin, is less potent against mycobacterial tuberculosis and the Mycobacterium avium complex. Clarithromycin (20%-40%) and its active metabolite (10%-15%) are excreted in urine. Of all the drugs in its class, clarithromycin has the best bioavailability at 50%, which makes it amenable to oral administration.
