Flashcards in Drugs & Bugs Unit II Deck (76)
Nisseria Meningitis Gram ?
3 Gram + Cocci
Localized, cutaneous abscess poss. after cut or foreign body
Catalase + --> fibrin capsule
created by bact AND host
Other pertinent infection property and what does it like to stick to?
Catalase Negative--> no abscess
sticks to foreign bodies - catheters, pacemakers, prosthetic hips etc
.nl. flora, usually not pathogenic in healthy ppl.
ClostridiumGram ?C or R
C. diff after antiB. tx --> nl. flora killed, C. diff prolif.
Killed by O2
Forms spores (endospores) which can tolerate O2
Staphylococcus major resistance problem?
How can penicillinase gene be transmitted from bact. to bact?
bacteriophage - plasmid
What does Beta-lactamase do?
Produced by bact., induced to do so by presence of penicillins,
Hydrolyzes beta lactams
PCN works on stage ? of c.w. synth?
Vanc. on stage ?
PCN, Ceph stage 3
Vanc. stage 2 --> works on MRSA
MRSA mode of resistance?
bact. alters its penicillin binding protein (stage 3 of c.w. synth)
Pen G doesn't work well on what type of bacteri?
Gr. ---> doesn't penetrate outer membrane very well
Oral Absorption for Pen G, V and Piperacillin?
Pen G - crappy
Pen V - good (acid stable)
Piperacillin - crappy - IV only
What is special about Dicloxacillin?
PCN-ase resistant and available orally
Give Piperacillin with what other drug? Why?
Tazobactam (Pip-Taz)--> is a Beta Lactamase inhibitor
--> effectively extends the spectrum of piper.
If you want low, sustained drug levels to fight endocarditis-syphilis, use what drug and what route?
Name two extended spectrum penicillins.
What are the additional bugs they are good for?
E. Coli, H. flu
Piperacillin's claim to fame bug?
Bacteroides (and other anerobes)
How are most Penicillins excreted and rough half-life?
half-life 1-2 hours
Name a drug that will block renal excretion of penicillins and what is its method of action?
Probenecid...blocks tubular secretion to prolong duration of action
Penicillin...weak acid? weak base?ionized or not at physiologic pH?
weak acidionized at phys. pH
Better oral absorption...Pen G or V?
More effective...Pen G or V?
Pen V. acid stable- better oral
Pen G - more effective used IV for hospitalized pts with serious infections
Penicillin G is awesome because...
powerful and inexpensive
Methicillin is no longer available...what drug has replaced its niche?
Draw-back of penicillinase-resistant penicillins?
less potent against Pen-G bugs
But good for PCN-ase producers
Prototypical penicillinase-resistant penicillin?
Spectrum of dicloxacillin?
What makes Amoxicillin and Ampicillin wider spectrum?
increased hydrophobicity ---> can penetrate porins of Gr (-) bugs
give in Amox in concert with Clavulanate to extend to PCN-ase bugs.
Which penicillin is anti-pseudomonal?
What are the other bugs it is good for?
also kills B. fragilis and enterococci (+AG)useful in anaerobic infections