Kaplan- Antibacterial Agents Flashcards
Which organism is treated with the synergistic regimen of penicillins + amino glycosides
Enterococci or Pseudomonas aeruginosa
Example of antagonistic effect = Penicillins + ______ to treat _____.
tetracyclines ; pneumococcal meningitis
Penicillins are ________ of cell wall synthesis.
bactericidal inhibitors
mechanism of resistance w. penicillin
Penicillinase (beta-lactamases) break lactam ring structure
Structural cahngs in PBPs
Change in porin structure
Penicillin Resistance to this organism? is caused by penicillinases (beta-lactamases) breaking lactam ring structure
Staphylococci
Penicilin Resistance to this organism? is caused by structural change in PBPs
methicillin-resistance Staphylococcus aureus [MRSA] , penicillin-resistant pneumococci
Penicillin REsistance to this organism? is caused by change in porin structure
Pseudomonas
Penicillin G active verses
- Streptococci
- Pneumococci (increased resistance)
- Meningococci
- Treponema pallidum
Penicillin V active verses
Steptococci
oral pathogens
oral, or IV extended spectrum penicillin
Ampicillin
oral extended spectrum penicillin
Amoxicillin
What are the extended spectrum penicillin antibiotics formulated w.
(ampicillin or amoxicillin) with clavulanic acid or sulbactam
Ampicillin and Amoxicillin active verses
Gram + cocci (except MRSA)
E. Coli
H. influenzae
What is Ampicillin active against that amoxicillin is not
Listeria monocytogense
Amoxicillin is also used for back up drug in _____ and to eradicate ______
Lyme disease
H. pylori in GI ulcers
increased activity verses gram negative rods compared to the other pencillins
Ticarcillin (Ticar)
Ticarcillin (Ticar) is active verses
Psudomonas aeruginosa and other gram - rods
How is activity of Ticarcillin enhanced
penicillinase inhibiors clavulanic acid or tazobactam
Timentin is what combo
Ticarcillin + clavulanate potassium
penicillin + aminogycosides is active verses
enterococci and psudomonal species
how are most penicillins secreted? half life?
active tubular secretion w. half life < 60 min
Which penicillins are largely eliminated in bile?
Nafcillin and oxacillin
Which penicillin undergoes enterohepatic cycling, but is excreted by kidneys?
Ampicillin
which penicillin is a repository form w. a half life of 2 wks?
Benzathine penicillin G
When is dose reduction needed w. penicillins?
major renal dysfunction
Common adverse effects of penicillins
Urticarial skin rash
severe anaphylaxis is possible
Common side effete of methicillin
Interstitial Nephritis
T/F Assume complete cross-allergenicity between individual penicillins
true
GI distress (NVD) is especially assoc with what penicillin
ampicillin
What is a common reaction in treatment of syphilis
Jarish-Herxheimer reaction
What is common adverse effect of ampicillin
maculopapular rash
common adverse effect of methicillin
interstitial nephritis
Name 3 first generation Cephalosporins
Cefadroxil (Duricef)
Cefazolin (Ancef, Kefzol)
Cephalexin (Keflex)
What do first generation cephalosporins protect against
Gram + Cocci (except MRSA)
E. coli
Klebsiella pneumoniae
some proteus species
common use of cephalosporins is
surgicla prophylaxis
which cephalosporins enter the CNS
NONE
Second generation cephalosporins active verses
increased gram - coverage including some anaerobes
Bacteroidesfragilis is covered w. which cephalosporin
Cefotetan (Cefotan)
H. influenzae & Moraxella entarrhalis is covered by which cephalosporin
Cefaclor
Third generation cephalosporins active verses
gram + & gram - cocci, plus many gram - rods
Which third generation cepaholsporin does NOT enter the CNS?
cefoperazone
What are 3rd generation cephalosporins important in empire management of
meningitis and sepsis
treatment of gonorrhea
ceftriaxone (Rocephin) (IM) and cefixime (Suprax) (PO) used in single dose
cephalosporin active against most most bacteria causing meningitis
cefotaxime (Claforan)
3rd generation Cephalosporin active agianst B. fragilis
Ceftizoxime (Cefizox)
name what most Fourth gerneation cephalosporins active against also name a specific antibiotic in this class
resistant to most beta-lactamases - Cefepime (IV)
Cephalosporins renal clearance similar to penicillins, with active tubular secretion blocked by ______.
probenecid
Dose modification in renal dysfunction, except _____ & _____, which is largely eliminated in the bile.
Cefoperazone & Ceftriaxone
Most authorities recommend avoiding cephalosporins in patients allergic to penicillins. For gram + organisms recommend _____.
For gram - rod organisms recommend _____.
+ macrolide
- rods aztreonam
Cefotetan, Cefoperazone, Cefamandole, Moxalactam cause
Hypoprothrombinema
& disulfiram-like-interactions w. ethanol
Adverse effect of IV injection of cephalosporins
phlebitis
IM adverse effect of cephalosporins
pain