2/12 Smith Antimicrobials 4

Question 1

Two enzymes used to convers PABA into folic acid which is used for AA, Pyramidines and purines

Answer 1

1) dihydropteroate synthetase

2) Dihydrofolate reductase

Question 2

What drug inhibits dihydropteroate synthetase?

Answer 2

Sulfamethoxazole (SMX)

Question 3

What drug inhibits dihydrofolate reductase

Answer 3

Trimethoprim (TMP)

Question 4

Why are SMX and TMP so selective?

Answer 4

BC humans lack enzymes to conver PABA into tetrahydrofolic acid(folic acid)

Question 5

What is silver sulfadiaxine?

Answer 5

a Topical sulfonamide antibiotic

Question 6

SMX bacteriostatic or bacteriod=cidal?

Answer 6

bacteriostatic

Question 7

Sulfadiazine clinical use

Answer 7

Oral monotherapy for UTIs and burns

Question 8

Silver Sulfadiazine

Answer 8

Topical treatment for infections on burns

Question 9

Adverse effects of sulfadiazine

Answer 9

Sulfa-hypersensitivity

Photosensitivity

Question 10

TMP mechanism

Answer 10

inhibits dihydrofolate reductase

Question 11

Adverse effect of TMP

Answer 11

C. Diff overgrowth. Pseudomembranous colitis

Question 12

When TMP and SMX are used together they become

Answer 12

bactericidal

Question 13

CLinical Uses TMP and SMX

Answer 13

PJP
Gram positive aerobes (recurrent UTI)
H. influenza