PHCY 402 Exam 2 Study
Guide
Beta-lactams: MOA - Answer inhibit bacterial cell wall synthesis
-inhibit transpeptidases (closely associated with penicillin-binding proteins)
-transpeptidases are the enzymes needed to cross-link peptidoglycan chains, and thus
prevent cell wall synthesis
-lesions on the cell wall lead to cell rupture
Beta-lacatams: bactericidal or bacteriostatic - Answer bactericidal
Beta-lactams: unique structure - Answer the chemical structure of the beta lactam ring
Beta lactams: mechanism of resistance - Answer 1) beta-lactamase production
2) modification of penicillin-binding proteins (PBPs)
3) reduced penetration of antibiotic to reach PBPs (less porins)
4) efflux pump
Penicillins: structure - Answer beta-lactam ring fused to a 5-sided ring
Penicillins: coverage - Answer not active against MRSA or atypicals
Pencillin DOC - Answer Tx for syphilis
Anti-staphylococcal penicillins DOC: nafcillin, oxacillin, dicloxacillin - Answer Tx for
MMSA
-the R group blocks beta-lactamases
Aminopenicillins + a beta-lactamase inhibitor - Answer -ex: clavulanate, sulbactam
-added activity against MSSA and more resistant strains of G-bacteria
Amoxicillin and Amoxicillin/Clavulanate (Augmentin) DOC - Answer Tx for otitis media
piperacillin/tazobactam (Zosyn) - Answer -only penicillin active against Pseudomonas
-broadest spectrum penicillin
Probenecid prevents - Answer penicillin from being secreted into the renal tubule for
, excretion in the urine, therefore increasing penicillin plasma levels and duration of
action
Penicillins: adverse effects - Answer hypersensitivity reactions, GI upset, rash,
hemolytic anemia, risk of seizures if accumulation occurs (depends on renal function)
Cephalosporins: structure - Answer beta-lactam ring fused to a 6-sided ring
Cephalosporins: coverage - Answer -generally, G- spectrum increases with generations
-not active against Enterococcus or atypicals
Cephalosporins: first gen coverage - Answer -G+ (streptococci, staphylococci, MSSA)
-PEK: some activity against G- rods (Proteus, E. coli, Klebsiella)
Cephalosporins: second gen coverage - Answer -streptococci, more resistant S.
pneumoniae
-HNPEK: Proteus, E. coli, Klebsiella, Haemophilus, Neisseria
Cephalosporins: third gen coverage - Answer -Resistant S. pneumoniae, MSSA
-HENPECKS: Proteus, E. coli, Klebsiella, Haemophilus, Neisseria, Enterobacter,
Citrobacter, Serratia
Ceftazidime - Answer -3rd generation cephalosporin
-HENPECKS + PsA + A: Adds pseudomonas and Acinetobacter but loses streptococcus
and MSSA (lacks G+ activity)
Cephalosporins: fourth gen coverage - Answer -Cefepime
-HENPECKS + PsA + A and add back streptococcus and MSSA
Cephalosporins: fifth gen coverage - Answer Ceftaroline
-only beta-lactam that covers MRSA
-HENPECKS (adds MRSA but loses pseudomonas and acinetobacter)
Cephalosporin combos with beta-lactamase inhibitors add - Answer activity against
multi-drug resistant G- rods
Cefiderocol - Answer -used in MDR G-
-Siderophore binds free iron to enter G- cell wall
Cephalosporins: adverse effects - Answer -hypersensitivity reactions (some
cross-reactivity with penicillin allergy)
-GI upset, rash, hemolytic anemia
Guide
Beta-lactams: MOA - Answer inhibit bacterial cell wall synthesis
-inhibit transpeptidases (closely associated with penicillin-binding proteins)
-transpeptidases are the enzymes needed to cross-link peptidoglycan chains, and thus
prevent cell wall synthesis
-lesions on the cell wall lead to cell rupture
Beta-lacatams: bactericidal or bacteriostatic - Answer bactericidal
Beta-lactams: unique structure - Answer the chemical structure of the beta lactam ring
Beta lactams: mechanism of resistance - Answer 1) beta-lactamase production
2) modification of penicillin-binding proteins (PBPs)
3) reduced penetration of antibiotic to reach PBPs (less porins)
4) efflux pump
Penicillins: structure - Answer beta-lactam ring fused to a 5-sided ring
Penicillins: coverage - Answer not active against MRSA or atypicals
Pencillin DOC - Answer Tx for syphilis
Anti-staphylococcal penicillins DOC: nafcillin, oxacillin, dicloxacillin - Answer Tx for
MMSA
-the R group blocks beta-lactamases
Aminopenicillins + a beta-lactamase inhibitor - Answer -ex: clavulanate, sulbactam
-added activity against MSSA and more resistant strains of G-bacteria
Amoxicillin and Amoxicillin/Clavulanate (Augmentin) DOC - Answer Tx for otitis media
piperacillin/tazobactam (Zosyn) - Answer -only penicillin active against Pseudomonas
-broadest spectrum penicillin
Probenecid prevents - Answer penicillin from being secreted into the renal tubule for
, excretion in the urine, therefore increasing penicillin plasma levels and duration of
action
Penicillins: adverse effects - Answer hypersensitivity reactions, GI upset, rash,
hemolytic anemia, risk of seizures if accumulation occurs (depends on renal function)
Cephalosporins: structure - Answer beta-lactam ring fused to a 6-sided ring
Cephalosporins: coverage - Answer -generally, G- spectrum increases with generations
-not active against Enterococcus or atypicals
Cephalosporins: first gen coverage - Answer -G+ (streptococci, staphylococci, MSSA)
-PEK: some activity against G- rods (Proteus, E. coli, Klebsiella)
Cephalosporins: second gen coverage - Answer -streptococci, more resistant S.
pneumoniae
-HNPEK: Proteus, E. coli, Klebsiella, Haemophilus, Neisseria
Cephalosporins: third gen coverage - Answer -Resistant S. pneumoniae, MSSA
-HENPECKS: Proteus, E. coli, Klebsiella, Haemophilus, Neisseria, Enterobacter,
Citrobacter, Serratia
Ceftazidime - Answer -3rd generation cephalosporin
-HENPECKS + PsA + A: Adds pseudomonas and Acinetobacter but loses streptococcus
and MSSA (lacks G+ activity)
Cephalosporins: fourth gen coverage - Answer -Cefepime
-HENPECKS + PsA + A and add back streptococcus and MSSA
Cephalosporins: fifth gen coverage - Answer Ceftaroline
-only beta-lactam that covers MRSA
-HENPECKS (adds MRSA but loses pseudomonas and acinetobacter)
Cephalosporin combos with beta-lactamase inhibitors add - Answer activity against
multi-drug resistant G- rods
Cefiderocol - Answer -used in MDR G-
-Siderophore binds free iron to enter G- cell wall
Cephalosporins: adverse effects - Answer -hypersensitivity reactions (some
cross-reactivity with penicillin allergy)
-GI upset, rash, hemolytic anemia
