Antibiotics Flashcards
Which penicillin is oral? IV/IM?
oral: pen V. IV/IM: pen G.
Penicillin mech
1) bind PBPs (transpeptidases) 2) block transpeptidase cross-linking of peptidoglycan. 3) Activate autolytic enzymes.
Clinical use of Penicillin
Gram + organisms (S. pneumoniase, S. pyogenes, Actinomyces). Also used for N. Meningitidis and T. Pallidum. Bactericidal for gram positive cocci, gram positive rods, gram negative cocci, and spirochetes. Penicillinase sensitive.
Penicillin Toxicity
Hypersensitivity reactions. Hemolytic anemia
Penicilin Resistance
Penicillinase in bacteria (a type of beta lactamase) cleaves beta lactam ring
Ampicillin, amoxicillin (aminopenicillins, penicillinase sensitive penicillins) Mechanism?
Same as penicillin but wider spectrum; penicillinase sensitive. Also combine with clavulonic acid to protect against beta lactamase.
Which has better oral bioavailability, ampicillin or amoxicillin?
amOxicillin (O for oral)
What is the clinical use of Ampicillin, amoxicillin (aminopenicillins, penicillinase sensitive penicillins)?
Extended-spectrum penicillin : HELPSS kill enterococci: Haemophilus influenzae, E. Coli, Listeria monocytogenes (meningitis in the elderly) Proteus mirabilis, Salmonella, Shigella, enterococci
Ampicillin, amoxicillin (aminopenicillins, penicillinase sensitive penicillins) SE?
Hypersensitivity reactions; rash; pseudomembranous colits
Ampicillin, amoxicillin (aminopenicillins, penicillinase sensitive penicillins) Mechanism of resistance?
Penicillinase in bacteria (a type of beta lactamase) cleaves beta lactam ring
Oxacillin, nafcillin, dicloxacillin (penicillinase resistance penicillins) mechanism?
same as penicillin. Narrow spectrum; penicillinase resistant because bulky R group blocks access of beta lactamase to beta lactam ring
Oxacillin, nafcillin, dicloxacillin (penicillinase resistance penicillins) clinical use?
S. aureus ( except MRSA; resistant because of altered PBP target site). Use naf (naficillin for staph)
Oxacillin, nafcillin, dicloxacillin (penicillinase resistance penicillins) toxicity?
hypersensitivity reactions, interstitial nephritis
Ticarcillin, piperacillin mech?
Same as penicillin. Extended spectrum.
Ticarcillin, piperacillin clinical use?
Pseudomonas spp. and gram-negative rods; susceptible to penicillinase; use with beta lactamase inhibitors.
Ticarcillin, piperacillin toxicity?
hypersensitivty reactions
What are the beta lactamase inhibitors?
Clavulanic Acid, Sulbactam, Tazobactam. Often added to penicillin antibiotics to protect the antibiotic from destruction by beta lactamase (penicillinase).
what are cephalosporins
beta lactam drugs that inhibit cell wall synthesis but are less susceptible to penisillinases
What organisms are typically not covered by cephalosporins?
they are LAME: Listeria, Atypicals (chlamydia, mycoplasma), MRSA, and Enterococci.
What Cephalosporin will cover MRSA?
Ceftaroline
What is the clinical use of 1st generation Cephalosporins?
gram positive cocci: PEcK : Proteus mirabilis, E. Coli, Klebsiella pneumoniae.
What are the 1st generation Cephalosporins?
cefazolin, cephalexin
which 1st generation cephalosporin is used prior to surgery to prevent S. aureus wound infections?
Cefazolin
What are the 2nd generation cephalosporin drugs/indications?
cefoxitin, cefaxcor, cefuroxime (gram positive cocci): HEN PEcKS: Haemophilius influenzae, Enterobacter aerogenes, Neisseria spp., Proteus mirabilis, E. coli, Klebsiella pneumoniae, Serratia