Rifampin has proved to be a valuable antibiotic with relatively few major adverse effects. Its
toxicity is predominantly hepatic and immunoallergic in character. While hepatic toxicity is
dose related and has been observed mainly in patients with underlying liver disease, the
immunoallergic effects are usually associated with intermittent or prolonged therapy. These
immunoallergic effects may be minor (a cutaneous, gastrointestinal, or influenzalike
syndrome) or major (hemolytic anemia, shock, or acute renal failure).