(See also Overview of Antibiotics.)
Rifamycins work by suppressing the bacteria's production of genetic material. As a result, the bacteria die.
Rifamycins include the following:
Rifampin, rifabutin, and rifapentine are used to treat similar infections (such as tuberculosis) and have similar side effects. Rifabutin is also used to treat infection due to Mycobacterium avium complex (MAC), which usually occurs only in people with a weakened immune system. These drugs are usually used with other antibiotics.
Rifaximin is used to treat traveler's diarrhea caused by Escherichia coli (E. coli).
Rifamycins are used during pregnancy only when the benefits of treatment outweigh the risks. With rifabutin, no harmful effects on the fetus have been observed in animal studies, but no well-designed studies have been done in pregnant women. With rifampin and rifapentine, harmful effects on the fetus (including birth defects) have been observed in animal studies.
Use of rifamycins during breastfeeding is not recommended. A decision to stop breastfeeding or to stop rifampin should be made depending on the importance of the drug to the mother's health.