Chapter 89: Drugs that weaken the bacterial cell wall II

Question 1

Cephalosporins

Answer 1

beta-lactam antibiotics (most widely used)
similar to penicillin structure
bacteriacidal

Question 2

Cephalosporin generation MOAs

Answer 2

suceptible to beta lactamase enzymes
1st generation are destroyed by beta lactamase
2nd generation are less sensitive to destruction
3rd, 4th, and 5th are highly resistant

Question 3

Cephalosporin routes of administration

Answer 3

usually given parenterally (IV)
poor absorption from GI, so only IV or IM
low toxicity

Question 4

Cephalosporin first generation therapeutic uses

Answer 4

For gram-positive staph and strep infections in patients with mild penicillin allergy
Cefazolin (Ancef, Keflex)

Question 5

Cephalosporin second generation therapeutic uses

Answer 5

Limited use (rarely used) for pneumonia, otitis, sinusitis, respiratory tract infections and abdominal and pelvic infections by specific organisms
Cefaclor (Ceclor)

Question 6

Cephalosporin third generation therapeutic uses

Answer 6

Drugs of choice for meningitis and nosocomial (hospital acq.) infections resistant to other drugs; gonorrhea
Ceftriaxone (Rocephin)

Question 7

Cephalosporin fourth generation therapeutic uses

Answer 7

CNS infections
Commonly used to treat health care and hospital associated pneumonias
Cefipime(Maxipime)

Question 8

Cephalosporin fifth generation therapeutic uses

Answer 8

MRSA
Ceftaroline (Teflaro)

Question 9

Cephalosporin Interactions

Answer 9

Probenecid = delays renal excretion

Alcohol = disulfiram-like reaction (Cefazolin &Cefotetan specifically)

Drugs that promote bleeding = increased bleeding (NSAIDs, warfarin, heparin)

Question 10

Do not use cephalosporins if pt has severe _______ allergy: may be cross allergy!

Answer 10

penicillin (PCN)

Question 11

Adverse Effects of Cephalosporins

Answer 11

Allergy – mainly rash (Anaphylaxis is rare)

Bleeding (cefotetan, ceftriaxone; interfere with vitamin K and prothrombin)

Thrombophlebitis –* Venous inflammation with thrombus formation

Pseudomembranous colitis – due to C-diff toxins (Overgrowth due to creating an imbalance with ABX)
injection site pain = give lidocaine

Question 12

Vancomycin class

Answer 12

glycopeptide

Question 13

Vancomycin Action

Answer 13

Bactericidal (effective against gram positive bacteria)
Inhibits cell wall synthesis
NO beta lactam ring

Question 14

Vancomycin therapeutic uses

Answer 14

Severe infections only
C. difficile assoc. pseudomembranous enterocolitis
Methicillin-resistant Staphylococcus aureus or Staph epidermidis (MRSA)
Usually IV –> Poor GI absorption, but oral effective for infections of GI tract

Question 15

Vancomycin interactions

Answer 15

renal excretion toxicity can lead to renal failure
pharmacists often dose and monitor levels
**Trough level **drawn just before the next dose
Peak levels drawn 1-2 hours after the completion of IV vancomycin dose

Question 16

Vancomycin Adverse Effects

Answer 16

-Ototoxicity (Reversible or permanent)
“Red person” syndrome or Red Man Syndrome
Thrombophlebitis (common)
Thrombocytopenia (rare)

Question 17

Infusion reaction (red man syndrome) of vancomycin

Answer 17

Too fast infusion causes hypotension and flushing
Administer at least over 60 minutes (give very slowly)

Question 18

Vancomycin resistance

Answer 18

Overuse has caused resistance
Many hospitals have strict criteria for use
VRE - vancomycin resistant enterococcus