Cell Wall inhibitors

Question 1

Mechanism of action of Penicillins

Answer 1

1. Bind to PBP

2. inhibit transpeptidase activity (cross linking)

Question 2

Most Penicillins are eliminated by renal tubular secretion, except:

Answer 2

Ampicillin and Nafcillin

Question 3

What are narrow spectrum antimicrobials, and what are they useful for?

Answer 3

Penicillin G and Penicillin V, and are useful against syphillis (Treponema pallidum)

Question 4

What are very narrow spectrum? What are they used for?

Answer 4

Dicloxacillin,Nafcillin,Methicillin

Staph. Aureus

Question 5

Why are narrow spectrum antimicrobials bad?

Answer 5

They are beta-lactamse sensitive

Question 6

What is MRSA? What can be used in its place?

Answer 6

PBP is changed, resistant to methicillin. Vancomycin.

Question 7

What are broad (extended) spectrum drugs?

Answer 7

Amoxicillin and Ampicillin

Question 8

Amoxicillin and Ampicillin work on

Answer 8

Gram +ve: Streptococci
Gram –ive: E. coli, H. influenzae, and Proteus, Listeria monocytogenes (Ampicillin),Borrelia Burgdorferi (Amoxycillin), H.Pylori (Amoxycillin) species.

Question 9

Antipseudomonal

Answer 9

Piperacillin, Carbenicillin

Question 10

Antipseudomal are affective against

Answer 10

Gm –VE rods inclusing pseudomonas aeruginosa

Question 11

Describe Narrow Spectrum Ring

Answer 11

R protects the lactam ring, but its small, therefore betalactamase attacks it.

Question 12

Describe Very narrow spectrum Ring

Answer 12

R is large, therefore cannot be attacked by betalactamase, but is only affective against Staph Aureus.

Question 13

Describe Extended (broad) spectrum ring

Answer 13

R group small, can pass through gram +/-, but is susceptible to betalactamase. Not affective against Pseudomonas

Question 14

You should give an broad/extended penicillin with?

Answer 14

Beta lactamase inhibitors - aminoglycosides.

Clavulanate ,Sulbactam & Tazobactam

Question 15

Bactericidal

Answer 15

Kills bacteria

Question 16

Bacteriostatic

Answer 16

Stops the growth. You need the immune system to get rid of it, therefore do no give to people with weak immune systems!

Question 17

Penicillins and cephalosporins should not be given together. True or false?

Answer 17

True

Question 18

Adverse effects of Penicillins

Answer 18

GI upset (mainly broad spectrum)
Hypersensitive of all 4 types

Question 19

Methicillin causes what adverse reaction?

Answer 19

Intestitial nephritis

Question 20

There is cross reactivity with all beta-lactam drugs except?

Answer 20

Aztreonam

Question 21

Very narrow spectrum drugs are resistant against?

Answer 21

Beta-lactamase because they have a large R group

Question 22

In cases of MRSA, use

Answer 22

Vancomycin