L12: Cell wall synthesis inhibitors Flashcards
briefly explain the mechanism of beta-lactam antibiotics .
they bind to penicillin binding site
then inhibit transpeptidase so that the cross linking does not take place in the cell wall
beta lactam antibiotics block the action of _____
transpeptidase
what’s the only type of organism that beta lactam antibodies is effective against ?
bacteria
which penicillin is natural ?
penicillin G
which penicillin is semi-synthetic and acid resistant ?
penicillin V
which semi-synthetic beta lactam antibiotic is penicillinase resistant ?
methicillin
give an example of a beta lactamase inhibitor .
clavulanic acid ( bonds IRREVERSABLY to beta lactamase , inhibiting it from hydrolysis of penicillin )
prophalaxis dosing and timing :::
3g given orally in divided doses
1 hour before surgery
used 5 days post operatively
list some adverse factors associated with penicillin .
hypersensitivity in 1-10% of patients
rash , urticaria , angioedema to anaphylaxis
diarrhea due to disruption of normal flora( particularly ampicillin )
nephritis with methicillin
neurotoxicity , seizure disorders
platelet dysfunction with carbenicillin , ticorcillin
what antibiotic is most likely to result in GI problems due to disruption of natural flora ?
ampicillin ( injected penicillin )
what beta lactam antibiotic can cause nephritis ?
methicillin
what are cephalosporins used as?
alternatives to penicillin ( very close)
-inhibits pbp enzyme
which generation of cephalosporins are used for orodental infections ?
1st and 2nd
which cepharosporins have high activity against gram positive (+ve) aerobes and good penetration into tooth socket ?
cephalexin / cephadroxil
adverse reactions for cepharosporins are very minimal but can include ::
allergic reactions , GI effects , nephrotoxicity , superinfection , and local reactions at site of injections
