USMLE Step 1 Antibiotics Quiz with complete solutions | Latest 2023/2024

USMLE Step 1 Antibiotics Quiz with complete solutions | Latest 2023/2024 Penicillin mechanism -- binds to penicillin binding proteins in peptidoglycan (blocks transpeptidase crosslinking); activates autolytic enzymes penicillin use -- gram positives and syphilis penicillin toxicity -- hypersensitivity reactions, hemolytic anemia penicillinase resistant penicillins -- methicillin, nafcillin, dicloxacillin penicillinase resistant penicillin use -- Staph aureus penicillin resistant penicillin toxicity -- hypersensitivity; methicillin: interstitial nephritis aminopenicillins -- ampicillin, amoxacillin aminopenicillin mechanism -- same as penicillin but wider spectrum aminopenicillin use -- select gram positive and negative bacteria--H flu, E coli, Listeria, Proteus, Salmonella, enterococci aminopenicillin toxicity -- hypersensitivity, ampicillin rash, pseudomembranous colitis antipseudomonal drugs -- ticarcillin, piperacillin, carbenicillin antipseudomonal mechanism -- same as penicillin; wider spectrum antipseudomonal use -- Pseudomonas and gram negative rods antipsuedomonal toxicity -- hypersensitivity reaction beta lactamase inhibitor mechanism -- inhibit beta lactamase (protects penicillins from destruction) beta lacatamase drugs -- clavulanic acid, sulbactam, tazobactam bacteriostatic antibiotics -- erythromycin, clindamycin, sulfamethoxazole, trimethoprim, tetracycline, chloramphenicol bactericidal antibiotics -- vancomycin, fluoroquinolones, penicillin, aminoglycosides, cephalosporins, metronidazole 1st generation cephalosporins -- cefazolin, cephalexin 1st generation cephalosporin coverage -- gram positive cocci, Proteus, E coli, Klebsiella cephalosporin mechanism -- beta lactams; inhibit cell wall synthesis but less susceptible to penicillinases 2nd generation cephalosporins -- cefoxitin, cefaclor, cefuroxime 2nd generation cephalosporin coverage -- same as 1st plus H flu, enterobacter, Neisseria, Srratia 3rd generation cephalosporins -- ceftriaxone, ceftazidime, cefotaxime 3rd generation cephalosporin coverage -- serious gram negative infections; ceftriaxone: Neisseria, ceftazidime: pseudomonas 4th generation cephalosporins -- cefepime