Antibiotics I

Question 1

beta-lactams

Answer 1

• Include: penicillins, cephalosporins, carbapenems, monobactam
• cell wall inhibitors by binding PBPs in cell membrane and inhibit crossliking = bactericidal
• side effects: anaphylaxis, rashes, BM suppressio, interstitial nephritis, GI (nausea, diarrhea, c.diff)

Question 2

PCNs

Answer 2

gram +, gram -, some anaerobes
1st generations: PCN
2nd generations: AMPICILLIN, AMOXICILLIN
3rd generations: METHICILLIN, NAFCILLIN, OXACILLIN, DICLOXACILLIN
4th generations: PIPERACILLIN, TICARCILLIN
*combined w/beta-lactam inhibitors:
1. AUGMENTIN (Amoxicillin/Clavulanate), UNASYN (ampicillin/sulbactam)
2. ZOSYN (Piperacillin/Tazobactam), TIMENTIN (Ticarcillin/Clavulanate

Question 3

Cephalosporins

Answer 3

• higher resistance to beta-lactamases, better anti-staph
• cross-reactivity w/ PCN allergy, but less w/ higher generations
• No coverage of enterococcus or atypicals.
• Only ceftazidime and cefepime cover pseudomonas
• Only Cefoxitin and cefotetan have anaerobic coverage

Question 4

Which is used for strep throat?
Which is used for URIs?
Which is best for MSSA?

Answer 4

• penicillin
• amoxicillin
• nafcillinn (anti-staph)

Question 5

Which combined pcn/bet-lactamase covers pseudomonas?

Answer 5

Zosyn and Timentin because they contain the 4th generation piperacillin and ticarcillin

Question 6

What are the advantages of using carbapenems? What is the major drawback?

Answer 6

broadest specturm- including ESBLs but at risk for seizures (esp imipenem)

Question 7

What group of bacteria are monobactams targeting?

What are the adavantages of using aztreonam?

Answer 7

only gram -

1. No cross-reactivity w/ PCN
2. No renal failure
   * if ceftazidime allery, avoid!

Question 8

How do macrolides work?
What are the major side effects?
What are they used for?

Answer 8

50S ribosomal inhibitor- bacteriostatic
rash, diarrhea, QT prolongation
Atypical coverage for zpack, GI motility agent for erythromycin

Question 9

How do tetracylcines work?
What are the major side effects?
What are they used for?

Answer 9

30S inhibitors- bacteriostatic
discoloration of teeth
Atypicals

Question 10

How do clindamycins work?
What is the major side effect?
What kind of coverage does it have?

Answer 10

50S inhibitor- bacteriostatic
causes highest rate of c. diff
anaerobes, gram+ cocci (not enetero though)

Question 11

How do aminoglycosides work?
What are the major side effects?
What is the coverage?

Answer 11

30S inhibitor- bacteriocidal
nephrotoxicity and ototoxicity
aerobic gram -