Answers
What is the mechanism of action for beta lactam antibiotics? - Answer-Inhibit cell wall
synthesis
/.What specific site in the cell wall is affected by beta lactam antibiotics? - Answer-Beta
lactam antibiotics antibiotics bind to the transpeptidase enzyme and block the formation
of the peptide cross-links. This results in a weak cell wall and osmotic lysis of the
bacterium
/.Name the 4 major classes of beta lactam antibitoics. - Answer-Penecillins
Cephalosporins
Carbapenems
Monobactams
And vancomycin, which does not fit into any of the above classes.
/.Name the 3 first generation cephalosporins and whether they are effective against
gram positive or negative organisms. - Answer-Cefadroxil
Cefazolin
Cephalexin
Better against gram positive organisms
/.State which organisms (positive or negative) are best treated by second and third
generation cepahlosporins, and review the drugs in each category. - Answer-Better for
gram negative
Second gen:
Cefaclor
Cefuroxime
Cefprozil
Third gen:
Cefdinir
Cefditoren
Cefixime
Cefotaxime
Cefotetan
Cefpoxodime
Ceftazidime
Ceftriaxone
, Ceftibuten
/.This generation of cephalosporins has both gram positive and negative coverage, and
are considered extended-spectrum drugs. - Answer-Fourth generation cephalosporins:
Cefditoren
Cefepime
/.Name the only fifth generation cephalosporin (and the first drug that was effective
against MRSA) - Answer-Ceftaroline
/.Describe the benefits of ertapenem, and when it may be used. - Answer-Ertapenem
can be given as a once daily dose at home (by a traveling nurse, etc) due to its longer
half-life
/.Which are the two "natural" penicillin? - Answer-Penicillin G and penicillin V
/.Which classes of beta lactam antibiotics are considered the "big guns" and why? -
Answer-Carbapenems and monobactams have a broader spectrum of activity and
greater potency than any other beta-lactam antibiotics. They are used with multidrug
resistant organisms.
/.Name the three common carbapenem drugs and which types of organisms they treat
(positive vs. negative). - Answer-Meropenem, imipenem, and ertapenem.
They treat most gram-positive, gram-negative, and anaerobic organisms
/.Name the only available monobactam and what it is used to treat (positive vs.
negative). - Answer-Aztreonam, which treats only gram negative bacteria.
/.Vancomycin is used only against gram ________ bacteria. - Answer-Positive.
/.This infusion reaction (which is not an allergy) stimulates a histamine-like reaction that
causes vasodilation leading to flushing and discomfort, and cardiac instability (decrease
in BP). - Answer-Red Man's Syndrome
/.Describe the mechanism of action for oritavancin (similar to vancomycin). - Answer-
Inhibits transglycosylation; inhibits transpeptidation; and DEPOLARIZES the bacterial
cell membrane resulting in increased permeability and cell death. Not used in children
(not enough data) at this time.
/.Aminoglycosides, chloramphenicol, macrolides, clindamycin, linezolid, and
quinupristin/dalfopristin all have the same mechanism of action. How do they affect
bacteria? - Answer-They inhibit protein synthesis within the cell by binding to ribosomal
subunits 30s or 50s.
/.Name the six most common aminoglycoside drugs. - Answer-Amikacin
Gentamicin