Mycobutin, generically known as rifabutin, is an antibiotic medication primarily used in the prevention and treatment of Mycobacterium avium complex (MAC), a type of bacterial infection that often affects people with HIV/AIDS. It is also used in certain cases to treat tuberculosis, especially in patients who cannot tolerate other standard treatments. Mycobutin works by inhibiting the action of bacterial RNA polymerase, a key enzyme necessary for the bacteria to replicate and spread, thereby stopping the infection from growing. It is part of a class of drugs known as rifamycins, which are known for their potent antimicrobial activity. Mycobutin is usually taken orally and can be used in combination with other antibiotics for more effective treatment of complex infections.