ID Beta-Lactams Flashcards
Penicillins MOA
Bind to PCN-binding proteins on bacterial cell wall/membrane; destroy cell wall by inhibiting transpeptidase (enzymes that cross-link peptidoglycan molecules to add strength) causing lysis (bacteriocidal)
Penicillins AE
Allergic reaction, n/v/d
Cephalosporins MOA
Bind to PCN-binding proteins on bacterial cell wall/membrane; destroy cell wall by inhibiting transpeptidase (enzymes that cross-link peptidoglycan molecules to add strength) causing lysis (bacteriocidal)
Cephalosporin AE
Cross-reactivity to penicillin; pseudomembranous colitits; bone marrow suppression; nephrotoxicity
Penicillins Prototype Drug
Penicillin G, Penicillin V
Cephalosporins Prototype Drug
First-generation: cephalexin; second-generation: cefaclor, cefuroxime; third-generation: ceftazidime; fourth-generation: cefepime
Carbapendems Prototype Drug
Imipenem (always combined with cilastatin to inhibit hydrolyzation by renal tubular dipeptidase)
Carbapendems MOA
Bind to PCN-binding proteins on bacterial cell wall/membrane; destroy cell wall by inhibiting transpeptidase (enzymes that cross-link peptidoglycan molecules to add strength) causing lysis (bacteriocidal)
Carbapendems AE
n/v, fever, imipenem may cause seizures
Glycopeptides Prototype Drug
Vancomycin
Glycopeptides MOA
Inhibit cell wall synthesis by attaching to the end of the peptidoglycan precursor units (D-alanyl-D-alanine terminus), thereby stopping peptidoglycan synthesis; bacteriocidal
Glycopeptides AE
Flushing (red man syndrome), neutropenia; in rare cases: ototoxicity when combined with another ototoxic agent & nephrotoxicity
Fluoroquinolones Prototype Drug
Ciprofloxacin
Fluoroquinolones MOA
Inhibit DNA gyrase (aka topoisomerase II) in gram-neg organisms and topoisomerase IV in gram-pos organims; bacteriocidal
Fluoroquinolones AE
Generally well-tolerated; n/v/d; tendon ruptures
Aminoglycosides Prototype Drug
Gentamicin
Aminoglycosides MOA
- Inhibit protein synthesis by irreversibly binding the 30S ribosomal subunit; at low concentrations, they cause misreading of the mRNA by ribosomes; at high concentrations, they halt protein synthesis, trapping ribosomes at the AUG start codon 2. create fissures and pores in the outer cell membrane, resulting in leakage of intracellular contents and increased antibiotic uptake
Aminoglycosides AE
Ototoxicity, nephrotoxicity (indicated by an increase in serum creatinine)
Lincosamides Prototype Drug
Clindamycin
Lincosamides MOA
Bind the 23S rRNA molecule of the 50S ribosome and inhibit peptidyl transferase, blocking the transfer of the new amino acid onto the growing chain; bacteriostatic; beneficial in toxin-producing infections
Lincosamides AE
Pseudomembranous colitis (extremely high incidence of C. diff)
Tetracyclines Prototype Drug
Tetracycline
Tetracycline MOA
First enter microorganism, then bind reversibly to 16S sununit of the 30S ribosome and inhibits translation; bacteriostatic; Demecloclycline inhibits the binding of ADH to its receptor
Tetracyclines AE
Significant n/v/d; mottling of teeth d/t Ca binding; photosensitivity; superinfection; diabetes insipidus; liver damage; kidney damage
Macrolides Prototype Drug
Erythromycin
Macrolides MOA
Bind to bacterial 50s ribosome and inhibit peptidyl transferase, blocking the transfer of the new amino acid onto the growing chain. Inhibition of protein synthesis does not typically kill bacteria cells, so these agents are generally bacteriostatic , but in high concentrations they can be bactericidal.
Macrolides AE
Significant GI upset due to increased gut motility; Acute cholestatic hepatitis . Are better tolerated but can also cause liver impairment
Oxazolidinones Prototype Drug
Linezolid
Oxazolidinones MOA
blocks the translocation step of protein synthesis by binding the 23S rRNA of the 50S RSU. Therefore bacteriostatic. Can also result in human mitochondrial suppression (mitochondrial inhibitor) causing rare but serous side effects.
Oxazolidinones AE
Rare but serious. Serotonin Syndrome, Hyperlactatemia and Metabolic Acidosis, Nerve Damage (neuropathies), and Hematologic (bone marrow suppression and low blood count)