Antifolate Drugs: Sulfa Drugs/Sulfonamides

Question 1

Sulfamethoxazole (Bactrim) component

Answer 1

Oral, IV

Question 2

Mechanism of Action

Answer 2

bacterial cells are impermeable to folic acid, reduce folic acid so bacteria dies

Question 3

Pharmocokinetics/ Drug Interactions

Answer 3

well absorbed orally, distributes through body water, metabolized in liver, excreted renally, drug interactions with other highly protein bound drugs (warfarin)

Question 4

Adverse Drug Reactions

Answer 4

GI intolerance, Nephrotoxicity, Kernicterus

Question 5

Hypersensitivity Reactions and Cross Sensitivity

Answer 5

3% of people are allergic, high rate of SJS and TEN (look at chart in notes)

Question 6

Trimethoprim

Answer 6

Antifolate Drug
Dihydrofolatre reductase=mechanism
folate deficiency in very high doses
Hyperkalemia

Question 7

Sulfamethoxazole/Trimethoprim also: Co-Trimoxazole (Bactrim, Septra)

Answer 7

combo of sulfonamide and antifolate

Question 8

Therapeutic Indications of Bactrim

Answer 8

UTI, Prostate infections, Otitis media, Pneumocystis jiroveci, CA-MRSA