Cell Wall Synthesis Inhibitors Flashcards
MOA for Penicillins
inhibit cell wall synthesis by interfering with formation of peptidoglycan layer
bind transpeptidase enzyme
bacteriocidal
Natural Penicillins
Penicillin G (gram +) Penillin V (gram +)
Penillin G
Gram +
IV or intramuscular administration
destroyed in acidic environment of digestive tract
Penicillin V
Gram +
Oral (more stable in acidic environment)
Take without food
Aminopenicillins
Gram -
Ampicillin
Amoxicillin
Ampicillin
Oral
Take with OUT food
Amoxicilin
Oral
Take with or without food
Penicillinase Resistant Penicillins
Gram +
Contain side groups that protect drugs from inactivation by B-lactamases
Methicillin, oxacillin, nafcillin (parenterally)
Dicloxicillin (orally)
Parenteral Penicillinase Resistant Penicillins
Methicillin, oxacillin, nafcillin
Oral Penicillinase Resistant Penicillins
Dicloxicillin
Anti-pseudomonal Penicillins
Gram -
Extended spectrum penicillins
Ticarcillin, Mezlocillin, pipercillin–parenterally
Carbenicillin–orally (therapeutic levels only reached in urinary tract)
Parenteral anti-pseudomonal penicillins
Ticarcillin, mezlocillin, pipercillin
Oral anti-pseudomonal penicillins
Carbenicillin–therapeutic levels only reached in urinary tract–limited to UTI’s and prostatic infections
Irreversible inhibitors of B-lactamases
NO anti-microbial activity by themselves!
must be combined with penicillins–> expanded coverage against B-lactamase producing organisms
Clavulanic acid, sulbactam, tazobactam
Cephalosporins
Cell-wall synthesis inhibitors
Structurally resemble penicillins
Difference: B-lactam chemical backbone
Stable to changes in pH
Take with or without food
Adverse Effects of Cephalosporins
Penicillin allergic patients may be hypersensitive to cephalosporins
GI irritation
Renal Toxicity–accumulation of drug may cause seizures
Disrupts normal flora–infections
Carbapenems
Bacteriocidal
Inhibit cell wall synthesis
Resistant to B-lactamases (unique different stereochemical structure of B-lactam ring)
Imipenem/cilostatin
Doripenem
Ertapenem
Meropenem
Telavancin
interferes with cell wall synthesis by binding D-Ala-D-Ala portion of cell-wall– blocks cross linking
Changes cell’s permeability–> may disrupt membrane potential
NOT affected by B-lactamases
Vancomycin
Interferes with cell wall synthesis by binding D-Ala-D-Ala portion of cell walls
NOT affected by B-lactamases
Given by IV
Reserved for MRSA
“Red man syndrome”–temporary flushing of skin when drug is given at high concentration too rapidly
Cycloserine
Gram +/-
Reserved to treat TB (mycobacterium tuberculosis)
Polymyxin B
Gram - (except Proteus)
Cationic detergent–disrupts lipoproteins in bacterial cell wall, increasing permeability
