anaerobic bacteria naturally reduce the prodrug metronidazole to its active form via an enzyme called ferredoxin. once reduced, it is postulated to lead to toxic products that result in DNA breakage and subsequent cell death.
metronidazole+ethanol (inhibits aldehyde dehydrogenase, resulting in buildup of toxic metabolites)
metallic taste, furring of the tongue
resistant to isoniazid and rifampin
resistant to isoniazid, rifampin, fluoroquinolones, 1+ second line drugs
primary vs secondary resistance
primary = initial infection, secondary = acquired during TB therapy
isoniazid + rifampin + pyrazinamide + ethambutol for 4 months, followed by isoniazid + rifampin (or alternate) for 2 months
isoniazid for 6-9 months
blocks formation of cell wall in organisms c mycolic acid, bacteriostatic.
optic neuroitis (decr vision, red/green issues)
prodrug activated by mycobacterial bacterial katG, inhibits mycolic acid synthesis by blocking InhA.