Part 2- Antimicrobial, antiseptic etc Flashcards
what ABX do we use to treat syphilis
PCN-highly effective
Higher doses of this drug is needed to treat gonococci due to resistance
PCN
PCN is the drug choice for these 5 infections
pneumococcal
streptococcal
meningococcal
Treating all forms of actinomycosis and clostridial infections causing gas gangrene
prophylactic administration of PCN is highly effective against ___infection
streptococcal infections, accounting for its value in pts with rheumatic fever
Clinical indications for PCN
Transient bacteremia occurs in the majority of patients undergoing dental extractions, emphasizing prophylactic need of PCN for those patient with cardiac issues and tissue implants.
Transient bacteremia can accompany procedures such as T&A, GU, GI, and vaginal deliveries
Penicillin G IV 10 million U contains 16 mEq of potassium - what is the concern with this potassium administration
patients with renal dysfunction
may result in neurotoxicity and hyperkalemia
IF PCN G is needed and the potassium content would promote a risk- what can be administered
a sodium salt of PCN G or a similar medication such as ampicillin or carbenicillin
anuria increases penicillin G by how many fold
10 fold
Slide 36
Slide 36
Major Resistance to PCN:
Bacterial produces B-lactamase enzymes
The hydrolyzed the B-lactam ring rendering it inactive
Drugs not susceptible to hydrolysis by staphylococcal penicillinases that would otherwise hydrolyze the cyclic amide bond of the B-lactam ring and render the antimicrobial inactive:
Methicillin Oxacillin Nafcillin Cloxacillin Dicloxacillin
Specific indications for these drugs are infections caused by staphylococci known to produce the staphylococcal penicillinases enzyme:
Methicillin Oxacillin Nafcillin Cloxacillin Dicloxacillin
what is nafcillin used for
Nafcillin can penetrate the CNS sufficient enough to treat staphylococcal meningitis
Extensive renal excretion for what three drugs
Methicillin
Oxacillin
cloxacillin
High dose Oxacillin therapy has been associated with
hepatitis
what can accompany Methicillin administration:
hemorrhagic cystitis and an allergic interstitial nephritis (hematuria, proteinuria)
what two drugs have superseded methicillin
oxacillin and nafcillin
what is the advantage of high dose therapy of nafcillin for patients with renal impairment
80% is excreted in the bile
unlike methicillin, oxacillin and nafcillin are relative stable in an acidic medium and adequately works in what form
PO form
what two drugs are available as PO medications and may be preferable over oxacillin and nafcillin d/t its ability to produce higher blood levels
cloxacillin and dicloxacillin
2nd generation PCN
ampicillin, amoxicillin and carbenicillin
2nd generation PCN- ampicillin, amoxicillin and carbenicillin. bactericidal against what bacteria?
Bactericidal against both gram positive and gram negative bacteria
what generation of abx provide wider range of activity than other PCNs
ampicillin, amoxicillin and carbenicillin 2nd gen
which drugs are not effective against most staphylococcal infections
2nd generation PCN
ampicillin, amoxicillin and carbenicillin
which drug has a broader ranger than PCN G
ampicillin
what does ampicillin cover
pneumocci, meningococci, gonococci, and various streptococci
what gram negative bacilli does ampicillin cover
Haemophilus influenza and Escherichia coli
is ampicillin well absorbed in the GI
Yes
in the first 6 hours of a PO dose of ampicillin how much is excreted unchanged by the kidneys
50%
ampicillin is among PCN’s associated with the highest incidence of ““This”” which typically appears 7-10dyas after initiation therapy
skin rash
the rash from ampicillin may not be true allergic reaction - what is it more associated with
protein impurities in commercial preparation
amoxicillin is chemically identical to what drug
ampicillin
even though amoxicillin and ampicillin are chemically identical- what is the advantage of amoxicillin
more efficiently absorbed from GI
concentrations of amoxicillin are present in the circulation how many times as long as ampicillin
2x’s
what generation is carbenicillin and what is it derived from
3rd generation
derivative of ampicillin
the principle advantage of carbenicillin is its effectiveness in Tx of infections cause by what
pseudomonas aerugingsa and certain proteus strains resistant to ampicillin
carbenicillin is penicillinase (b-lactamase) susceptible and ineffective against most strains of
s. Aureus.