Other Antimicrobials Flashcards
Nitrofurantoin
(Damage DNA - bactericidal)
(UTIs by Gram - Rods, E. coli (TMP-SMX resistant))
Reduced by bacterial enzymes to intermediates that damage DNA - concentration dependent
Admin: Oral
Exclusive Renal Excretion (20-60m)
Metronidazole
(Damage DNA - bactericidal)
(ANAEROBES - C perf, C diff, B fragilis)
Transformed into radical anion that damages DNA
Admin: Oral
Extensive penetration, incl CSF and bone
Hepatic Excretion
Nitrofurantoin - Resistance
Pseudomonas
Nitrofurantoin - Side Effects & Drug Interactions
SE: Anorexia, nausea, vomitting, diarrhea, Neuropathy w/chronic use, possible teratogen - Macrocrystalline forms better tolerated
DI: N/A
Metronidazole - Resistance
Nitroimidazole reductase
Metronidazole - Side Effects & Drug Interactions
SE: Should not be used while breast-feeding; headache, dry mouth, metallic taste, vomiting, diarrhea, candidal superinfections
DI: possible with CYP450 inhibitors/inducers –> altered by alcohol use by inhibiting alcohol dehydrogenase (Antabuse rxn)
Trimethprim-Sulfamethoxazole
(Inhibits Folic Acid synthesis - Bacteriostatic/cidal)
(Broad spectrum)
(Staph (MSSA, MRSA), E coli, pseudomonas, Chlamydia)
Sulfonamide - PABA analog
Trimethprim - inhibits dihydrofolatereductase
Admin: Oral (no food, high fluids)
Wide distribtuion in fluids, incl CSF and placenta
Hepatic and Renal Excretion
Trimethprim-Sulfamethoxazole - Resistance
Escape mechanisms via methionine, purines, and thymine, acquired via increases in PABA or altered DHPS/DHFR
Trimethprim-Sulfamethoxazole - Side Effects & Drug Interactions
SE - displaces protein bound bilirubin, fever, rash, agranulocytosis, aplastic anemia, serum sickness, anaphylaxis, SJS, Renal damage, hemolytic anemia, anorexia, nausea, vomiting, diarrhea
DI: Sulf - increases effects of antigoagulants and hypoclycemic via displacement
Trimeth - hyperkalemia with ACE inhibitors, angiotensin receptor blockers, or aldosterone antagonists
