Antimycobacterials Flashcards
Isoniazid
- Anti-TB 1st line
- Inhibits cell wall synthesis (kills actively growing bacteria) – prodrug activated by catalase/peroxidase from KatG gene – competitor for Enoyl-ACP reductase
- Peripheral neuropathy, elevation of liver enzymes, fatal hepatitis
- Combination for active TB, single drug for latent TB
Ethambutol
- Anti-TB 1st line
- Inhibits cell wall synthesis – active against multiplying bacilli - interferes in cell wall arabinogalactan biosynthesis
- Optic neuritis (decreased visual acuity, red-green colorblindness)
- Bacteriostatic
Pyrazinamide
- Anti-TB 1st line
- Disrupts membrane and energy metabolism – prodrug metabolized by pyrazinamidase
- Hepatotoxicity, GI intolerance
- Can kill dormant TB (use in first 2 months)
Rifampin
*Anti-TB 1st line
Anti-leprosy
*Inhibits mRNA synthesis – active against rapidly growing and slow metabolizing bacilli – rapidly penetrates tissus and phagocytic cells – inhibits prokaryotic RNA polymerase (binds to beta subunit to prevent mRNA transcription)
*Orange color to urine/ sweat/tears, rashes, thrombocytopenia, nephritis, hepatitis
Interacts with P450 and other drugs
Resistance from rpoB gene mutation (sign of MDR)
*Bactericidal – broad spectrum of gram +/- bacteria
Pauci bacillary and multi-bacillary leprosy
Buruli ulcers
Capreomycin
- Anti-TB 2nd line
- Block protein synthesis (16S rRNA, 70S ribosome, rRNA methyltransferase)
- TB
Ciprofloxacin
- Anti-TB 2nd line
- Block DNA synthesis by targeting DNA gyrase
- TB
Cycloserine
- Anti-TB 2nd line
* Inhibit cell wall peptidoglycan synthesis (D-alanine analog)
Ethionamide
- Anti-TB 2nd line
* Block mycolic acid synthesis/cell wall – targets acyl carrier protein reductase
Kanamycin
- Anti-TB 2nd line
* Block protein synthesis (16S rRNA)
Dapsone
- Anti-leprosy
- Inhibits bacterial synthesis of dihydrofolic acid leading to inhibition of DNA and RNA synthesis
- Hemolysis, hepatitis, nausea, rash
- Leprosy
