Antibiotics-Drugs, MOAs, adverse effects, key features. Flashcards
B-lactam compounds
Penicillins, cephalosporins, monobactams, carbapenems.
B-Lactam common traits
Are bactericidal, all contain a lactam ring, susceptible to B-lactamase
Penicillin compounds MOA
Bind to and inhibit PBP enzymes. PBPs play important role in synthesis and maintenance of bacterial cell wall peptidoglycan
Penicllin compounds key adverse effects
Hypersensitivity Rxn: Rash, hives, itching, respiration diffulcty, anaphylaxis (w/ anaphylaxis, expect cross reactivity)
Narrow spectrum B-lactam drugs, key features, and sensitive organisms
Penicillin G and V. B-lactamase sensitive.
Sensitive organisms: streptococci, pneumococci, meningococci, Treponema pallidum
Very Narrow Spectrum B-lactam drugs/key features/sensitive organisms
Methicillin, nafcillin, oxacillin. B-lactamase RESISTANT
Sensitive organisms: Staphylococci (not MRSA)
Broad spectrum B-lactam drugs/key features`
Ampicillin, amoxicillin. B-lactamase sensitive
Extended spectrum B-lactams
Piperacillin, Ticarcillin, Azlocillin. B-lactamase sensitive.
Sensitive organisms: Gran-negative rods, antipseudomonal
B-lactamase inhibitors MOA
Inhibit bacterial B-lactamase-often given with a B-lactam antibiotic
B-lactamase key adverse effects
Similar to penicillin agent that it is administered with
Cephalosporins MOA
Similar to penicillins, bind to and inhibit Penicillin binding proteins (PBPs). Generally more resistant to B-lactamase
Cephalosporins key adverse effects
Hypersensitivity
Cephalosporin-Sensitivity vs. Generation
As you go from 1st to 4th generation cephalosporin, the drugs go from more specific to less specific (1st gen=very specific, 4th generation=broad spectrum)
1st Generation cephalosporin selectivity
Gram + cocci
1st Generation cephalosporin-Agents
Cefazolin, Cephalexin
1st generation cephalosporins- key features
Used for surgical prophylaxis, does NOT enter CNS
2nd Generation Cephalosporin Agents
Cefotetan, Cefaclor, Fefuroxime
2nd gen cephalosporin key features
do NOT enter CNS, EXCEPT for cefuroxime
3rd Generation Cephalosporin agents
Ceftriaxone, Cefotaxime, Cefdinir, Cefixime
3rd Gen Cephalosporin key features
Most enter CNS, Used in treating meningitis and sepsis
4th Gen cephalosporin agents
Cefepime
4th gen cephalosporin key features
B-lactamase resistant, enter CNS, broadest spectrum
Monobactam (aztreonam) MOA, clinical use
Bind to and inhibit PBPs. Can penetrate the cerebrospinal fluid.
Used to treat serious infections=>pneumonia, meningitis, and sepsis.
B-lactamase resistant
Monobactam (aztreonam) adverse effects
Hypersensitivity=>skin rashes and itching, not as concerned w/ anaphylactic rxns.
Carbapenems MOA
Bind to and inhibit PBPs. B-lactamase resistant, but susceptible to a similar enzyme (carbamenemase).
Carbapenems adverse effects
GI: Nausea, vomiting, and diarrhea
Vancomycin MOA/ TX
Prevents elongation of peptidoglycan cell wall structure by binding to the D-ala-D-ala pentapeptide and acting as a steric inhibitor.
Used to treat MRSA, enterococci, and C. dif.
Vancomycin adverse effects
Skin: flushing (red neck or “red man syndrome”).
Vancomycin Tissue penetration
Good tissue penetration except for CNS
Bacitracin MOA
Blocks incorporation of amino acids and nucleic acids into the cell wall
Bacitracin-adverse effects
Hypersensitivity rxns-rare
Where is bacitracin commonly found?
In topical and ophthalmic ointments, often combined w/ other antimicrobial agents
Fosfomycin MOA
Blocks an early step in cell wall synthesis=>prevents synthesis of UDP-N-aceylmuramic acid
Fosfomycin is commonly used in what?
Uncomplicated UTIs in females=>broad spectrum
Classes that are bacterial protein synthesis inhibitors
aminoglycosides, macrolides, tetracycline and “others”
Aminoglycosides MOA
Binds to 30s and blocks formation of initiation complex (step 1).
Used in combo w/ B-lactams to treat serious gram (-) infections.
Aminoglycosides adverse effects
Nephrotoxicity=>renal tubular necrosis
Ototoxicity=> dizziness, ringing, fullness
Macrolides MOA
Binds to 50s and impairs the translocation of “P” site (step 4)
Macrolides adverse effects
GI: stomach cramps, nausea, vomiting, diarrhea (motilin receptor agonist)