Antimycobacterial Drugs

Question 0

M. avium-intracellulare drugs

Answer 0

• Prophylaxis: Azithromycin

- Treatment: Azithromycin, rifampin, ethambutol, streptomycin

Question 1

M. tuberculosis drugs

Answer 1

• Prophylaxis: Isoniazid

- Treatment: Rifampin, Isoniazid, Pyrazinamide, Ethambutol

Question 2

M. leprae drugs

Answer 2

• Prophylaxis: None

- Treatment: Dapsone, rifampin, clofazimine

Question 3

Isoniazid (INH)

Answer 3

• MOA: Decreases synth of mycolic acids
  
  1. bacteria catalase-peroxidase needed to convert INH to active metabolites
• Use: TB; only solo prophylaxis
• Toxicity: Neurotoxicity, hepatotoxicity, lupus
  
  1. Vit B6 can prevent neurotoxicity and lupus

Question 4

Rifampin

Answer 4

• MOA: Inhibits DNA-dependent RNA polymerase
• Use: TB
  
  1. Delays resistance to dapsone when used for leprosy
  2. Meningococcal prophylaxis in H. influenzae contacts
• Toxicity: hepatotoxicity, increased P-450, and orange body fluids

Question 5

Pyrazinamide

Answer 5

• MOA: Inhibits mycolic acid production by blocking mycobacterial fatty acid synthase 1.
  
  1. Effective in acidic pH of phagolysosomes where TB located
• Use: TB
• Toxicity: Hyperuricemia, hepatotoxicity

Question 6

Ethambutol

Answer 6

• MOA: Decreased carbohydrate polymerization of mycobacterium cell wall by blocking arabinosyltransferase
• Use: TB
• Toxicity: optic neuropathy