Mycobacterial Infections

  1. What are first line drugs for TB?
    Isoniazid, rofampin, ethambutol, pyrazinamide (IREP)
  2. What's the treatment regimine for Active TB
    Combination Therapy!!
  3. What's the MoA of Isoniazid?
    Inhibit synthesis of mycolic acids (myco cell wall)
  4. What are the absorption/metabolism of isoniazid?
    • Absorption: GI --> body fluids/tissues
    • Activation: KatG enzyme
    • Inactivation: acetylation
  5. What drug interactions exist for isoniazid?
    Inhibits hydroxylation of phenytoin
  6. What are toxicities of Isoniazid?
    Neurotoxicity, hepatotoxicity (with EtOH), allergic reactions
  7. What's common resistance mechanism for isoniazid?
    Mutation of KatG gene (prevent activation)
  8. What's the MoA of Rifampin?
    • Inhibits bacterial DNA dependent RNA polymerase
    • Bacteriocidal
  9. What are the Absorption/excretion of Rifampin?
    • Absorption: GI
    • Excretion: orange-red coloration of urine
  10. What are clinical uses of rifampin?
    • first line TB with isoniazid
    • Menigococcal prophylaxis, HiB meningitis
  11. What are SE/interactions of rifampin?
    • SE: well tollerated; jaundice, rashes, thromocytopenia, flu-like illness
    • Interactions: induce CYP450 enzymes
  12. What is a resistance mechanism for Rifampin?
    mutation in DNA dependend RNA polymerase
  13. What's the MoA of Ethambutol?
    Inhibit synthesis of arabinogalactan
  14. What's the absorption/excretion of ethambutol?
    • Absorption: GI
    • Excretion: Kidney-Urine
  15. What are SE of ethambutol?
    Few; neuritis (color blindness)
  16. What's the resistance process for ethambutol?
  17. What's the MoA of Pyrazinamide?
    Inhibit fatty acid synthase I (mycolic acid synthesis)
  18. What are pharmacokinetics/SE of Pyrazinamide?
    • SE: Hepatotoxicity (not for gout pts)
    • Activation/resistance: pyrazinamidase
  19. What are guidelines for TB chemotherapy?
    2+ drugs for 6+ months
  20. When are second line TB agents used?
    • First line resistance
    • Failed response
    • Expert toxcicity management
  21. What are secondline TB drugs?
    • Fluoroquinolones
    • Streptomycin
    • Ethionamide
    • Aminosalicytic Acid
    • Cycloserine
  22. What are Rx for Mycobacterium Complex?
    Clarithromycin or Azithromycin AND ethamutol
  23. What's Rx for Hansen's Disease (Leprosy)
    • Dapsone + Rifampin
    • Multibacillary: Dapsone + Rifampin + Clofazimine
    • Paucibacillary: rifampin, minocycline, and ofloxacin
  24. What's the SE of Dapsone?
  25. What's SE of Clofazimine?
    GI, red coloring of skin
  26. What's SE of Thalidomide?
    Birth defects
  27. What are the SE of Streptomycin?
    Ototoxicity and nephrotoxicity
  28. What are SE of Ethionamide?
    Gastric irritation, metallic taste, neurologic symptoms
  29. What are SE of Aminosalicylic Acid (PAS)?
    GI Symptoms, Drug fever
  30. What are SE of Cycloserine?
    CNS dysfuntions and psychotic reactions
Card Set
Mycobacterial Infections
TB Drugs