Introduction Drugs rifamycins isoniazid pyrazinamide ethambutol dapsone clofazimine streptomycin Clinical use Classic Treatment Paradigm for Mycobacteria Organism Prophylaxis Treatment Mycobacterium tuberculosis Isoniazid Active infection: RIPE therapy Rifampin Isoniazid Pyrazinamide Ethambutol Latent infection: isoniazid x 9 months Mycobacterium avium-intracellulare Azithromycin Rifabutin Azithromycin + ethambutol Can also add rifabutin or ciprofloxacin Mycobacterium leprae Tuberculoid: dapsone + rifampin Lepromatous: dapsone + rifampin + clofazimine Anti-Mycobacterial MedicationsDrugMechanism of ActionAdverse EffectsNotesRifamycins (rifampin and rifabutin)Inhibits DNA-dependent RNA polymeraseHepatotoxicityRed or orange body fluidsCYP450 inducerRifabutin has less CYP450 effect, thus favored for HIV patientsMutations occur due to decreased binding to RNA polymeraseResistance occurs rapidly if used as monotherapyIsoniazidInhibits synthesis of mycolic acidsHepatotoxicityInhibits CYP450Drug-induced systemic lupus erythematosusVitamin B6 deficiencyperipheral neuropathysideroblastic anemiaco-administer with pyridoxine (B6) to reduce side effectsMay be used as monotherapy for prophylaxis and latent TB Mutations occur due to underexpression of enzyme required to convert drug into active metabolitePyrazinamideUnknown but may work through host phagolysosomesHepatotoxicityHyperuricemia-EthambutolInhibits arabinosyltransferase and disrupts cell wallOptic neuropathyred-green color blindness-DapsoneInhibits dihydropteroate synthesis (anti-folate)MethemoglobinemiaHemolysis (G6PD deficiency patients)-ClofazimineDisrupts DNAGastrointestinal upsetDry skinPink/brown skin and body fluid dyspigmentation-StreptomycinInteracts with 30S ribosomal subunitTinnitusVertigoAtaxiaRenal toxicitySecond-line treatment forM. tuberculosis Anti-Mycobacterial Medications Drug Mechanism of Action Adverse Effects Notes