Microbiology: Antimicrobials Flashcards
What are the adverse effects with Vancomycin?
alters peptidoglycan synthesis- D Ala to D Lac, works for drug resistant gram +, nephrotoxic, ototoxic, thrombophlebitis, DRESS syndrome
When should you use carbapenems?
When it’s a serious life threatening infection- covers gram positive, gram neg rods and anaerobes. Significant CNS tox, rash , GI distress
Monobactams?
Aztreonam- gram neg rods only, prevents peptidoglycan
What’s the mechanism of aminoglycosides, tetracyclines and macrolides?
protein synthesis inhibitors, small ribosome 70S
Aminoglycosides (gentamicin, tobramycin)- require O2 for uptake so can’t kill anaerobes
-think about nephrotoxicity, neuromuscular blockade and ototoxicity
What is chloramphenical?
Used in developing countries because low cost, but toxicity. For meningitis (H influ, neisseria, Step pneumo)- blocks peptidyltransferase 50S ribsome
What’s the valuable difference between metronidazole and clindamycin?
Clinda is used for anaerobes above the diaphragm, but Metronidazole is used for anaerobes below the diaphragm
** clindamycin can cause pseudomembranous colitis, blocks peptide transfer at 50S ribsome
What are the macrolides and their side effects?
azithromycin, clarithromycin, erythromycin- MACRO-motility issues (GI), cholestatic hepatitis, prolonged qt (arrhythymia), rash,eosinophilia
How do sulfonamides work?
folate synthesis, SMX is bacteriostatic but then cidal if you combine with TMP
Lots of side effects- G6PD hemolysis, nephrotoxicity, hypersensitivity, photosensitivity, stevens-johnson syndrome, kernicterus in infants
What should you worry about with trimethoprim?
inhibiting folate synthesis in combo with SMX so megaloblastic anemia, granulocytopenia, leukopenia
What are fluoroquinolones?
ciprofloxacin, levofloxacin, act on the prokaryotic topoisomerase 2 and 4- gram neg rods- urinary and GI tract
-contraindicated in preg, breastfeeding children <18y because of abnormal cartilage and prolonged qt
What does metronidazole do?
forms toxic free radicals in bacterial cell
works for giardia, entamoeba, gardenella vaginalis, anaerobes, can be used for H pylori
-headache, metallic taste, hypotension and tachycardia with alcohol
THINK anaerobes below the diaphragm vs clindamycin is anaerobes above the diaphragm
Which of the TB treatments requires B6 supplementation?
Isonazid- causes peripheral neuropathy, sideroblastic anemia, hepatoxicity, decreases cytochrome P450, drug induced SLE
-only monotherapy for TB and used in latent TB
Which TB drug causes optic neuropathy?
ethambutol- works on cell membrane (blocks arabinosyltransferase)
How does oseltamivir work?
blocks neuroaminidase so you can’t release viral progency
