how does rifampin work?
<answer> Rifampicin increases the activity of enzymes in the liver that break down various medicines. 1 As a result, rifampicin can increase the removal of many medicines from the body, making them less effective. <context> Rifampicin increases the activity of enzymes in the liver that break down various medicines. 1  As a result, rifampicin can increase the removal of many medicines from the body, making them less effective. Medicines affected in this way by rifampicin include those listed below.