miscellaneous beta lactams and other inhibitors of cell wall synthesis Flashcards
what is a monobactam active against G- aerobes?
aztreonam
which drug’s mechanism is binding to penicillin-binding-protein-3 (PBP-3) of G- bacteria?
aztreonam
aztreonam is given via ____ and is excreted _____ in urine
IV, unchanged
which drug is given as IV for MRSA or MSSA if allergic to beta-lactams?
vancomycin
when given orally, which drug that’s not normally absorbed orally is used for local action for pseudomembranous colitis from C. diff?
vancomycin
which drug’s mechanism is via binding to D-ala-D-ala terminus to prevent the removal of terminal D-ala of the pentapeptide chain attached to N-acetylmuramic acid residues of peptidoglycan?
vancomycin
ototoxicity, nephrotoxicity, and red man syndrome are side effects of which drug that inhibits cell wall synthesis?
vancomycin
what is red man syndrome’s mechanism and outcome?
histamine is released, causing vasodilation and a decrease in BP (hypotension) which leads to reflexive tachycardia to compensate and sometimes ends in shock. flushing of upper body and face also occurs
is vancomycin static or cidal?
static for G+ cocci and cidal for gram + rods
what is a cidal lipoglycopeptide for G+ skin infections that
- binds to D-ala-D-ala to inhibit cross linking
- disrupts bacterial membrane potential and increases membrane potential to cause cell lysis?
telavancin
what are the side effects of telavancin?
NVD, taste disturbance, foamy urine, could be teratogenic in pregnant woman
what lipoglycopeptide is used for ABSSSI’s from G+ organisms including MRSA that
- inhibits polymerization
- inhibibing crosslinking
- disrupting membrane integrity to increase permeability and cause cell lysis?
oritavancin
side effects of oritavancin?
NVD, headache, limb and SQ abscesses, C. diff and induced colitis
which drug is contraindicated with IV unfractionated heparin (coagulant) for 48 hours after administration due to aPTT test remaining falsely elevated?
oritavancin
what is a cidal semisynthetic lipoglycopeptide for ABSSI that has same mechanism as vancomycin?
Dalbavancin
side effects for dalbavancin?
nausea, diarrhea, headache
what drug is cidal vs various G+ cocci and bacilli rods that works by preventing dephosphorylation of bactoprenol carrier (which when dephosphorylated, attaches NAG/NAM to growing peptidoglycan chain), thus inhibiting cell wall synthesis?
bacitracin
what drug inhibits enolpyruvate transferase, blocking the addition of phosphoenolpyruvate to UDP-N-acetylglucosamine, the second step in synthesis of park nucleotide leading to inhibition of cell wall synthesis?
fosfomycin
what class of drugs are two amino sugars attached in glycosidic links to an aminocyclitol ring?
aminoglycosides
what class of drugs are cidal, very polar polycations usually given IV, or sometimes given orally to clean out the bowel?
aminoglycosides
what class of drugs works by flowing down their concentration gradient to enter G- bacteria through porin channels to
a) inhibit initiation of protein synthesis
b) cause misreading of mRNA, creating faulty proteins
c) cause premature termination of protein synthesis
aminoglycosides
are aminoglycosides effective against anaerobes and why?
no b/c anaerobes don’t have an electron transport chain for aminoglycosides to pass through to disrupt the cell
which class of drugs can cause post-antibiotic effects in G-rods and how?
aminoglycosides- by breaking up polysomes into non-functional monosomes that can continue to suppress bacterial growth and cause cell death long after drug falls below minimal inhibitor concentration
what class of drug mostly for G- organisms can be used with B-lactams for synergism and G+ coverage? what’s the mechanism for synergism?
aminoglycosides, B-lactams inhibit cell wall synthesis and thus facilitate penetration of aminoglycosides
aminoglycosides attain their highest levels in?
renal cortex causing reversible nephrotoxicity and endolymph of inner ear causing irreversible ototoxicity
ototoxicity can result in what two things?
Auditory Sx and vestibular Sx
which rx’s can accumulate in fetal plasma leading to neonatal ototoxicity?
aminoglycosides
what are the GI drugs for G- coverage?
neomycin (used for bowel surgery) and paromomycin and they are both aminoglycosides
what two drugs are interchangeable and used for burns, wounds, and ophthalmic for G- coverage?
gentamicin and tobramycin-both aminoglycosides
what is used for nosocomial infections that are resistant to gentamicin and tobranycin?
amikacin
what drug is gender specific for uncomplicated UTI’s in women?
fosfomycin
aminoglycosides are generally given ____x a day and why?
1, b/c of significant post-antibiotic effect
what does the cockcroft-gault formula give you and what do you need to find it?
clearance (how much blood volume of creatinine is cleared per minute) and you need to know the pt’s age, lean wt, and serum creatinine levels
true or false: the peak and trough levels for Gent/tobra and amikacin are similar.
false! they are significantly different
what drug class should not be used in conjunction with a neuromuscular blocker during anesthesia and why?
aminoglycosides b/c it can cause neuromuscular block leading to respiratory paralysis
what is the mechanism for neuromuscular block?
aminoglycosides block calcium uptake, thus decreasing ACh released, and it also blocks ACh receptors
what are alternatives when taking neuromuscular blockers?
giving IV calcium to increase the uptake of ca or giving neostigmine instead of aminoglycosides (neostigmine is a AChase inhibitor that increases ACh levels which stimulates respiratory muscles
what should you avoid giving to pts with myasthenia gravis and why?
aminoglycosides b/c myasthenia gravis is an autoimmune disease with an antibody against nicotinic receptors at the neuromuscular junction, creating extreme muscle weakness. aminoglycosides can also block the receptor exacerbating the condition
