Week 3 Cell Wall Inhibitor Drugs Flashcards
Penicillin V and Penicillin G
V= oral G= IV form
Probenecid
impairs renal secretion of weak acid, used to increase half life of penicillin
Nafcillin
penicillinase-resistant penicillin
Dicloxacillin
Penicillinase-resistant penicillin
Clavulanate
Beta-lactamase inhibitor
sulbactam
Beta-lactamase inhibitor
tazovactam
Beta-lactamase inhibitor
Ampicillin
Aminopenicillin
Amoxicillin
Aminopenicillin
Piperacillin
Antipseudomonal penicillin
ticarcillin
antipseudomonal penicillin
Cephalosporin
Inhibits cell wall synthesis by binding to penicillin binding protiens
less susceptible to penicillinases but can be inactivated by extended spectrum beta-lactamases
Carbapenems
Imipenem/cilastatin, meropenem
contain beta-lactam ring and bind to penicillin binding proteins
broad but MRSA resistant
GI distress, cross allergic, renal dysfunciton
Aztreonam
monocyclic beta lactams (use if patient is allergic to penicillin)
cell wall inhibitor and binds to polypeptide binding protein
gram neg rods
Vancomycin
binds with high affinity to the D-alanyl-D-alanine terminus of the cell wall precursor unit, inhibitng release from the bactopreno carrier, thus preventing synthesis. Inhibits TRANSGLYCOSLASE reaction
gram +, especially MRSA and C.diff
empiric treament
Bacitracin
prevents dephosphorylation of bactoprenol carrier needed for elongation of peptidoglycan cell wall NOT A BETA-LACTAM
topical, nephrotoxic when give IM
Daptomycin
binds to cell membrane and aggregates leading to depolarization of membrane and cell death, bactericidal
Only gram +
Side effects- reversible organizing pneumonia binds pulmonary surfactant accumulating in pulmonary spaces
Polymyxin B
binds phosphatidylethanolamine in the membrane creating holes, ultimately leading to release of cellular contents
Multidrug resistant gram negative bacilli, use in combo with other antibiotic to facilitate entry
Beta-Lactam Antibiotics Mechanism of Action
binds to pencillin binding proteins of transpeptidase (which catalyze the terminal reaction in bacterial wall synthesis) and inhibits. Build up of cell wall precursors, which leads to activation of autolytic enzymes) Cell wall inhibitors weaken the cell wall when water enters through osmosis, cell bursts.
Penicillinse- resistant penicillins
Nafcillin, Dicloxacillin
Same mechansim as penicillin but have larger R groups so resistant to penicillinases. Effective against ONLY GRAM +
Aminopenicillins
Ampicillin, Amoxicillin
Expanded spectrum, GRAM POS AND GRAM NEG
More water soluble and can pass through porin channels
Same mechanism as penicillin, susceptible to beta-lactamases
Antipseudomonal Penicillins
Ticarcillin, piperacillin
Widest spectrum, GRAM POS<, GRAM NEG, and PSEUDOMONAS
Same mechanism as penicillin, susceptible to beta-lactamases
1st generation cephalosporin
Gram + cocci
surgical prophylaxis
Can’t cross blood brain barrier
2nd generation cephalosporin
Gram Neg AND Gram Pos
use immediately prior to surgery to prevent infection
Can’t cross blood brain barrier
3rd generation cephalosporin
Strep and more serious Gram NEG that are resistant to other beta-lactam
CAN cross blood brain barrier
4th generation cephalosporin
BROADEST spectrum
GRAM POS, GRAM NEG, and PSEUDOMONAS
5th generation cephalosporin
Binds penicillin binding protein 2a in MRSA (mrsa has low affinity for other beta-lactams)
Imipenem
carbapenem, beta lactam ring and binds to penicillin binding proteins, broad but MRSA is resistant.
Administered with cilastatin- decrease cleavage of the beta-lactam ring by renal dehydropeptidase I and prevent formaiton of potentially toxic nephrotoxic metabolite
Meropenem
Carbapenems
Cilastatin
administered with Imipenem to decrease cleavage of the beta-lactam ring by renal dehyrdopeptidase I and prevent formation of potentially toxic nephrotoxin