Microbiology Flashcards
MOA penicillin G and V
- Prototype Beta lactam Abx
- Binds pencillin binding proteins known as transpeptidase and blocks cross linking of peptidogylcans. Activates autolytic enzymes
What is penicillin used to treat?
- think Gram Positive
- N Meningitidis
- Syphilis
- it’s cidial for all of the above
- it is also pencillinase sensitive
ADE of penicillin
HSR rxn, hemolytic anemia
MOA of ampicillin and amoxicillin
same as penicillin but can wider spectrum use.
- Amoxicillin has better oral bioavailability than ampicillin
- sensitive to penicillinase
What can you combine w/ ampicillin and amoxicillin to fight beta lactamases?
clavulanic acid
What are ampicillin and amoxicillin used to treat?
- Extended spectrum penicillin - H influenza, E. Coli, Listeria monocytogenes, Proteus mirabilis, Salmonella, Shigella, enterococci
- thinks HELPSS kill enterococci
ADE of ampicillin and amoxicillin
HSR rxn, rash, pseudomembranous colitis
MOA of oxacillin, nafcillin, and dicloxacillin
Same as penicillin but narrower spectrum.
- Have a bulky R group that block access of Beta lactamase to beta lactam ring
uses for oxacillin, nafcillin, and dicloaxcillin
S Aureus (except MRSA - resistant b/c of altered penicillin binding protein target site)
ADE of oxacillin, nafcillin, and dicloaxcillin
HSR rxn and intersitital nephritis
MOA of antipseudomonals penicillins (ticarcillin and piperacillin)
same as penicillin, extended spectrum
- use w/ Beta lactamase inhibitors to treat Pseudomonas and gram negative rods
ADE of antipseudomonal penicillin
HSR rxn
What are you beta lactamase inhibitors?
clavulanic acid, sulbactam, taxobactam,
MOA of cephalosporins
Beta lactam drugs that inhibit cell wall synthesis but are less susceptible to penicillinases
- cidial
What organisms aren’t typically covered by cephalosporins?
think LAME
- Listeria
- Atypical - chylamidia, mycoplasma
- MRSA - (exception - ceftaroline)
- Enterococci
What are the 1st gen cephalosporins and what do they treat?
Cefazolin and cephalexin
- gram positive cocci
PEcK: Proteus, E. coli, Klebsiella
When is cefazolin used?
before surgery to prevent S aureus wound infxns
What are teh 2nd gen cephalosporin and what do they treat?
Cefoxitin, cefaclor, cefuroxime
- gram positive cocci
HEN PEcKS : H flu, Enterobacter, Neisseria, Proteus, E. Coli, Klebsiella, Serratia
What are your 3rd gen cephalosporins and what do they treat?
Ceftriaxone, cefoxtaxime, ceftaxidine
- serious gram negative infections resistant to other beta lactams
1. ceftriaxone - meningitis and gonorrhea
2. ceftaxidime - Pseudomonas
What are your 4th gen cephalosporins and what do they treat?
Cefepime : increased activity against Pseudomonas and gram positive organisms
What are your 5th gen cephalosporins and what do they treat?
Ceftaroline
- broad gram positive and gram negative coverage
- MRSA but NOT Pseudomonas
ADE of Cephalosporins
- HSR Rxn
- Vit K deficiency
- Low cross reactivity w/ penicillins
- increased aminoglycosides mediated kidney toxicity
MOA of Aztreonam
monobactam, resistant to Beta lactamases
- prevents peptidoglycan cross linking by binding to penicillin binding protein
- syngergistic w/ aminoglycoside
- no cross allergenicity w/ penicillin
Uses of aztreonam
Gram negative rods only
- for penicillin allergic pts and those w/ renal insufficiency who can’t tolerate aminoglycosides