Used in the treatment and prevention of tuberculosis. Combinations are used in the treatment of active disease tuberculosis to rapidly decrease the infectious state and delay or prevent the emergence of resistant strains. In selected situations, intermittent (twice weekly) regimens may be employed. Streptomycin is also used as an antitubercular. Rifampin is used in the prevention of meningococcal meningitis and Haemophilus influenzae type b disease.