Clarithromycin

Clarithromycin is derived from erythromycin. It is better absorbed compared with erythromycin. Clarithromycin and erythromycin are virtually identical with respect to antibacterial activity except that clarithromycin has high activity against H. influenzae, M. leprae and T. gondii. Clarithromycin penetrates most tissues, with concentrations equal to or exceeding serum concentrations. It is metabolized in the liver. A portion of active drug and major metabolite is eliminated in the urine. It has drug interactions similar to those described for erythromycin. The advantages of clarithromycin compared with erythromycin are lower frequency of gastrointestinal intolerance and less frequent dosing.