May result from metabolite, acetylhydrazine. There is some contribution from alcoholic hepatitis. Reversible vasculitis may occur and arthritic symptoms at various joints may be observed. Other mycobacteria have variable sensitivity. Many chlamydiae are sensitive.
Resistance Can develop quickly.
Must not use the drug alone because of this. Resistance has developed in as little as 2 days in meningococcal carrier states. Mechanism of Action Mechanism of action is via inhibition of DNA-dependent RNA polymerase at the initiation step. Elongation is not inhibited. Rifampin binds to the beta-subunit of the holoenzyme.