8. Penicillins Flashcards
natural Penicillins
Penicillin G
penicillin V (oral)
(blue)
——————————————————————————–MOA (green)
-Beta Lactam Ring interferes with transpeptidation reaction of bacterial cell wall synthesis
-pBP forms peptidoglycan cross links, penicillin’s will halt peptidoglycan synthesis in the cell walls: bactericidal
Delivery
- penicillin V is acid stable and only used in minor infections due to poor bioavailability (oral)
- administered IV (pen G)
Used to Treat
-against gram (+) organisms (Staph and Strep)
-Oral Penicillin V treats streptococcal pharyngitis
(“Red bandanna”)
- Penicillin G or V treats rheumatic fever
- Strep Viridians endocarditis
-GBS prophylaxis
- Actinomyces Israeli
- Clostridium Perfringens causing gangrene
- pastuerella pen g
- benzathine pen g treats syphilis (spirochete)
- penicillin G - treats Neisseria meningitides
Resistance
Beta Lactamases are immune to penicillin
(“Beta Trooper shooting down a ship”)
-beta lactamases expressed by plasmid genes (“Circular shape”)
Adverse Reactions
Type 1 IgE mediated hypersensitivity reaction
(“Astronaut shutting eyes w/ IgE missiles on ship”)
-drug-induced autoimmune hemolytic anemia
(+ direct coombs test) (“Exploding asteroids w/ IgG”)
-drug induced interstitial nephritis
(“Kidney shaped nebula”)
anti staph penicillin
Nafcillin
Oxacillin
Dicloxacillin
- bulky R-groups prevent beta-lactamase binding
- Narrow spectrum, only activity against staphylococci
- empiric treatment for skin and soft tissue infections (folliculitis, abscesses)
Tricuspid pyramids: treatment for staph endocarditis
Fish bones: treatment for Staph osteomyelitis
broad spectrum penicillins
+beta lactamase inhibitors
- *Amoxicillin**
- amoxicillin – oral bioavailability
amoxicillin and ampicillin to treat strep throat
- amoxicillin treats otitis media and sinusitis caused by strep pneumoniae, Haemophilus influenza, moraxella catarrhalis
- amoxicillin and ampicillin treat pneumonia caused by strep pneumoniae, H. influenza
H Wing ship: activity against Haemiphilus influenza
-amoxicillin is part of the triple therapy (with clarithromycin and a PPI) for helicobacter pylori infection
- amoxicillin treats Lyme Disease caused by Borrelia burgdorferi
- amoxicillin prophylaxis against encapsulated bacteria (s. pneumo, H. Flu) in asplenic patients
- Amoxicillin prophylaxis before dental procedures in patients at high risk for endocarditis
Ampicillin
–IV administration
- ampicillin treats anaerobic infections (enterococcus)
- Gram Positive enterococcus
- ampicillin resistant strains of Enterococcus due to beta-lactamase production
- ampicillin treats meningitis caused by Listeria monocytogenes
- activity against gastrointestinal and urinary tract gram (-) rods
-sensitive to beta-lactamases
(typically used with clavulanate)
Piperacillin/Ticarcillin
- Paired with beta lactamase inhibitors to prevent cleavage of beta lactamases
- piperacillin and ticarcillin treat anaerobic infections,
- active against pseudomonas
**Beta lactamase inhibitors
Sulbactam
Tazobactam
Calvulanate**