Clofazimine and liposomes enhance the susceptibility of intracellular Mycobacterium avium toward rifabutin

The effects of rifabutin and clofazimine were studied on intracellularly growing Mycobacterium avium . Both drugs showed concentration-dependent inhibition of growth but no cidal effect at concentrations that can be reached in human serum. However, a combination of both drugs, even at lesser concentrations, exhibited cidal activity. Liposomes enhanced the susceptibility of the organism towards rifabutin but had no effect on the susceptibility towards clofazimine.