Metronidazole

Day 1: Known as an antibiotic with anti-parasitic properties, #metronidazole was discovered in the 1960s for efficacy against amoebic dysentery. This led to the accidental discovery of activity against anaerobic bacterial infections with expanded use in 1970s

Day 2: #metronidazole treats protozoal & anaerobic infections age > 1 month old e.g. H.pylori, G.vaginalis. Used in treatment of complex infections e.g diabetic foot infection. Used orally & i.v, as well as topically for rosacea & intravaginally for bacterial vaginosis. Prophylaxis & tx animal bites. Standard oral dosing 400mg x 3/day

Day 3: Good oral absorption/bioavailability. High Vd across placenta & BBB with penetration into most body tissues. Hepatic breakdown via oxidation & glucuronidation. Predominantly renal excretion. Elimination t½ 6-10 hrs. Caution/dose reduction severe hepatic impairment. No adjustment needed for renal failure. #metronidazole is not known to be harmful in pregnancy or lactation

Day 4: #metronidazole is activated by metabolism once inside an anaerobic bacterial cell via reduction/ferredoxins. This leads to free radicals, DNA damage & bactericidal effects. Aerobic cells/tissues can uptake but cannot activate, so the antibiotic is selectively cytotoxic to facultative anaerobic microorganisms