Microbiology--Pharmacology Flashcards
Penicillin G ,V use
G+ organisms: S pneumoniae, S pyogenes, Actinomyces, Also used for N meningitidis, T pallidum
Ampicillin, amoxicillin use
H flu, E coli, Listeria, Proteus, Salmonella, Shigella
Oxacillin, nafcillin, dicloxacillin
S aureus–has bulky R group to prevent penicillinase breakdown
antibiotic that can cause pseudomembranous colitis
ampicillin, amoxicillin
Ticarcillin, piperacillin
antipseudomonals–use with B lactamase inhibitors like tazobactam
what are organisms typically not covered by cephalosporins?
LAME: listeria, atypicals (chlamydia, mycoplasma), MRSA, Enterococci
1st generation cephalosporin
cefazolin, cephalexin–gram+ and PEcK: proteus, e coli, Klebsiella
2nd generation cephalosporin
cefoxitin, cefaclor, cefuroxime–gram +, and HEN PEcKS: h flu, enterobacter, Neisseria spp, Proteus, E coli, Klebsiella, Serratia
3rd generation cephalosporin
ceftriaxone, cefotaxime, ceftazidime; use ceftriaxone in meningitis and gonorrhea; use ceftazidime in pseudomonas
4th generation cephalosporin
cefepime–increased activity against pseudomonas and G+ organisms
5th generation cephalosporin
ceftaroline–broad gram+ and - coverage including MRSA, but does NOT cover pseudomonas
toxicities of cephalosporins?
vit K deficiency; low cross reactivity with penicillis; greater nephrotoxicity than aminoglycosides
what is a monobactam?
aztreonam–prevents peptidoglycan cross linking by binding to PBP3. Synergistic w/ aminoglycosides; no cross reactivity with penicillin
aztreonam uses?
gram - only; no activity against g+ or anaerobes; use in penicillin allergics or renal failure patients who can’t tolerate aminoglycosides
What is imipenem always administered with?
cilastatin–inhibitor of renal dehydropeptidase I
Which carbapenem is stable to dehydropeptidase I
meropenem
carbapenem tox?
GI distress, skin rash, CNS toxicity (seizures)–last resort bug
Vancomycin MoA?
inhibits cell wall peptidoglycan formation by binding D-ala Dala portion of cell wall precursors; resistance forms when AA modified to DalaDlac
Vancoymcin use?
only for G+, MRSA, enterococci, C diff
Vancomycin tox?
NOT; nephrotoxicity, ototoxicity, thrombophlebitis, diffuse flusing (red man syndrome)–prevent with antihistamines and slow infusion rate
Which antibacterial protein synthesis inhibitors target which ribosome?
buy AT 30; CCEL at 50: 30S: aminoglycosides, tetracyclines; 50S: chloramphenicol, clindamycin, erythromycin (macrolides), linezolid
What are some aminoglycosides?
Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin
aminoglycoside MoA:
30S: inhibit formation of initiation complex and cause misreading of mRNA; also blocks translocation; requires O2 for uptake so ineffective against anaerobes
aminoglycoside use?
severe gram negative rod infections; synergistic with B lactam anbx; neomycin for bowel surgery;