Drugs: Cell Wall Synthesis Inhibitors

Question 1

What does probenecid do?

Answer 1

prolongs the half life of penicillin by decreasing renal filtration

Question 2

What are Nafcillin and Dicloxacillin used for?

Answer 2

• antistaphylococcal penicillin (penicillinase resistant)
• very narrow spectrum (used against MSSA)
• large R group so resistant to penicillinase
• bactericidal

Question 3

What are the 4 types of beta lactams?

Answer 3

• penicillin
• cephalosporin
• carbapenems
• aztreonam

Question 4

What is penicillin used to treat?

-what are Penicillin V, G, procain, and benzathine?

Answer 4

• gram positive bacteria
• V= oral
• G= IV form
• procain and benzathine are for intramuscular administration

Question 5

What are Clavulinate, Sulbactam, and Tazobactam?

Answer 5

-penicillinase inhibitors
Clavulinate with penicillin, amoxicillin, and ticarcillin
Sulbactam with ampicillin
Tazobactam with Piperacillin

Question 6

What are Ampicillin and Amoxicillin used for?

Answer 6

Aminopenicillins

-Gram negatives (H. influenza, E. coli, Listeria, Salmonella)

Question 7

What are Ticarcillin and Piperacillin used for?

Answer 7

Antipseudomonals

-broad activity against Gram negative bacilli (including Pseudomonas)

Question 8

What are Monobactum and Aztreonam used for?

Answer 8

for patients allergic to penicillin

• Gram negative rods (Klebsiella, Pseudomonas, Serratia)
• only beta lactam drug specific for gram negative

Question 9

1st generation Cephalosporins: cefazolin

Answer 9

• gram positive cocci
• surgical prophylaxis
• can’t cross blood brain barrier

Question 10

2nd generation Cephalosporins: Cefoxitin, Cefuroxime, Cefotetan

Answer 10

• gram positive and some gram negatives
• don’t cross blood brain barrier
• can stop vitamin K synthesis (prolong bleeding)

Question 11

3rd generation Cephalosporins: Ceftriaxone, Cefotaxime

Answer 11

• for streptococci and serious Gram negative infections resistant to other beta lactams
• can cross blood brain barrier
• Ceftriaxone interacts with calcium to form crystals in kidneys and lungs
• broad spectrum

Question 12

4th generation Cephalosporins: Cefepime (cefazolin from gen 1 + ceftazidime from gen 3)

Answer 12

-broadest spectrum gram positive and gram negative (includes Pseudomonas)

Question 13

5th generation Cephalosporins: Ceftaroline

Answer 13

• only for MRSA (binds penicillin binding protein 2a in MRSA)
• low affinity for other beta lactams

Question 14

What are the Carbapenems (Imipenum/ Cilastatin and Meropenem)?

Answer 14

-beta lactam ring and bind penicillin binding protein
-low susceptibility to beta lactamase
broad spectrum

Question 15

What is Vancomycin?

Answer 15

• not a beta lactam (binds D-alnyl-D-alanine terminus)
• bactericidal
• gram positive (esp MRSA and C.diff)
• orally is poorly absorbed

Question 16

What is bacitracin?

Answer 16

• prevents dephosphorylation of bactoprenol carrier in peptidoglycan synthesis
• topical treatments

Question 17

What is Polymyxin B?

Answer 17

binds to phosphatidylethanolamine in membrane creating holes in membrane

• to treat multidrug resistant gram negative including Pseudomas aeruginosa
  ex) neosporin

Question 18

What is Daptomycin?

Answer 18

binds cell membranes to cause depolarization

-gram positive bacteria