Mechanisms of Action of Anti-infectives

Question 1

Inhibit protein synthesis by binding with 30S subunit causing alterations in cytoplasmic membrane

Answer 1

Tetracyclines (doxycyline, tetracycline)

Question 2

Interferes with bacterial protein synthesis by binding to 30S subunit resulting in defective bacterial cell membrane

Answer 2

Aminoglycosides (neomycin, amikacin, tobramycin, gentamicin)

Question 3

Binds to 50S ribosomal subunit resulting in blockage of transpeptidation

Answer 3

Macrolides (azithromycin, clarithromycin, erythromycin)

Question 4

Reversibly binds to 50S subunit preventing peptide bond formation resulting in inhibition of bacterial protein synthesis

Answer 4

Lincosamide (clindamycin)

Question 5

Binds to 50S subunit inhibiting protein synthesis

Answer 5

Streptogramins (quinupristin/dalfopristin)

Question 6

Reversibly binds to 50S subunit preventing amino acids transfer and protein synthesis formation

Answer 6

Chloramphenicol

Question 7

Binds to 50S subunit thus preventing the formation of a functional 70S initiation complex resulting in the inhibition of bacterial protein synthesis

Answer 7

Oxazolidinone (linezolid)

Question 8

Reactive intermediates alter bacterial ribosomal protein and other macromolecules leading to inhibition of protein synthesis, aerobic energy metabolism, DNA, RNA and cell wall synthesis

Answer 8

Nitrofurantoin

Question 9

Binds to bacterial isoleucyl transfer-RNA synthetase resulting in the inhibition of protein synthesis

Answer 9

Mupirocin

Question 10

Inhibits RNA synthesis by binding to the beta subunit of DNA-dependent RNA polymerase, blocking RNA transcription

Answer 10

Rifampin

Question 11

Inhibits relaxation of supercoiled DNA and promotes breakage of double-stranded

Answer 11

Fluoroquinolones (ciprofloxacin, ofloxacin, levofloxacin, moxifloxacin)

Question 12

Inhibits cell wall synthesis by inhibiting the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls

Answer 12

Penicillins (PCN G, PCN VK, dicloxacillin, oxacillin, nafcillin, amoxicillin, ampicillin, ticarcillin, piperacillin)
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Cephalosporins (cefazolin, cephalexin, cefuroxime, cefoxitin, ceftriaxone, cefotaxime, ceftazidime, cefdinir, cefpodoxime, cefepime, ceftaroline, ceftolozane, cefiderocol)
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Carbapenems (ertapenem, imipenem, meropenem)
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Monobactam (aztreonam)

Question 13

Inhibits bacterial cell wall synthesis by preventing transfer of muropeptides into the growing cell wall

Answer 13

Bacitracin

Question 14

Inhibits dihydrofolic acid reduction to tetrahydrofolate resulting in sequential inhibition of enzymes of the folic acid pathway

Answer 14

Trimethoprim

Question 15

Binds to components of the cell membrane resulting in rapid depolarization and inhibition of intracellular synthesis of DNA, RNA and protein

Answer 15

Lipopeptide (daptomycin)

Question 16

Binds to phospholipids, alters permeability, and damages the bacterial cytoplasmic membrane permitting leakage of intracellular constituents

Answer 16

Polymyxins (colistin, polymyxin B)