Osteomyelitis due to Mycobacterium haemophilum in a cardiac transplant patient: case report and analysis of interactions among clarithromycin, rifampin, and cyclosporine.

We describe a case of osteomyelitis due to Mycobacterium haemophilum in a cardiac transplant recipient and review the two other reported cases of M. haemophilum infection in cardiac transplant patients. Our patient had an excellent response to a prolonged course of therapy with clarithromycin and rifampin. We examine in detail the interactions between these two antibiotics and cyclosporine, including the apparently offsetting effects of clarithromycin/rifampin combination therapy on blood levels of cyclosporine.