Chapter 7 anti-infective agents - bactericidal cell wall inhibitors

Question 1

penicillins and cephalosporins

Answer 1

• inhibits crosslinking of cell wall components

effects
* hypersensitivity
* rare nerve, liver or kidney toxicity

Question 2

vancomycin
dalbavancin
oritavancin
telavancin

Answer 2

• prevents transfer or cell wall precursor from plasma membrane to cell wall (precursor is linked to existing cell wall by transpeptidase // one of several penicillin binding proteins needed for baceterial cell wall)

indication
* drug of choice for penicillin or methicillin-resistant staph and strep infections (gram +)
* bacteriostatic against enterococcus (species of streptococcus)
* oral — c. difficile colitis

effects
* thrombophlebitis ( swollen or inflamed vein due to a blood clot. )
* nephrotoxicity
* red man syndrome (rapid IV) — tachycardia, flushing, paresthesias, hypotension, severe nephrotoxicity

PO/IV

poor CNS penetration

Question 3

bacitracin

Answer 3

• inhibits recycling of carrier which transports cell wall presurcors across plasma membrane

indication:
* gram positive organisms infecting skin + eyes

effects
* nephrotoxiciticy when given IM

combination w/ polymxin or neomycin as topical agent

Question 4

imipenem/cilastatin (primaxin)
meropenem (merrem)
ertapenem (invanz)
doripenem (doribax)

carbapenem

Answer 4

• inhibits crosslinking of cell wall components

indication
* drug of choice – acinetobacter (gram neg)
* excellent coverage of most gram pos and neg (including those with b-lactamases) + pseudomonas aeruginosa (gram neg)

• similar to penicillin — hypersensitivty + rare nerve, liver, or kidney toxicity

IM/IV — imipenem rarely causes sterile bowel (d/t low conc of drug in bowel); imipenem admin w/ cilasatin to prevent renal breakdown (if renal failure then reduce dose of both)

Question 5

aztreonam (azactam)

monobactum

Answer 5

• inhibits crosslinking of cell wall components

indication
* great for gram negatives + p. aeruginosa (HA infections)
* not active against gram positives

effects
* similar to penicillin – hypersens. + rare nerve, renal, liver toxicity
* GI Upset

wide distribution including joints, brain, and urine

Question 6

daptomycin

lipopeptides

Answer 6

• depolarizes bacterial cell wall

indication
* skin infections d/t s. aureus, MRSA, strep species, and enterococcus (species of strep, vanco-sensitive d/t bacteriostatic ==> gram (+)

effects
* hepatotoxic
* diarrhea