USMLE step 3 - drug MOA (indications): Updated Solution

Erythromycin (Ans- 50S ribosome, inhibits TRANSLOCATION (movement of tRNA-aa from acceptor site to peptidyl site) clindamycin, chloramphenicol (Ans- 50 ribosome, inhibits PEPTIDYL TRANSFERASE (incorporation of new a.a.'s into growing strand) Linezolid (Ans- 50S protein synthesis inhibitor tetracycline (Ans- 30S ribosome, blocks tRNA-aa from binding to ACCEPTOR SITE on mRNA aminoglycosides (Ans- 30S ribosome, blocks INITIATION of translation and induces PREMATURE TERMINATION or mistranslation vancomycin (Ans- binds D-ala-D-ala portion of cell wall precursors, prevents POLYMERIZATION OF PEPTIDOGLYCANS cephalosporins (Ans- beta-lactam, with with some resistance to penicillinase ampicillin, amoxicillin (Ans- beta-lactam, broader spectrum but still susceptible to penicillinase ticarcillin, piperacillin (Ans- beta-lactam, broad-spectrum Rifampin (Ans- blocks mRNA transcription by inhibiting mRNA POLYMERASE beta subunit metronidazole (Ans- interacts with microbial ferredoxins to produce CYTOTOXIC INTERMEDIATES fluoroquinolones