Folate Inhibitors

Question 1

Sulfonamides preperations

Answer 1

Oral, absorbable
short acting: sulfisoxazole
medium acting: sulfamethoxazole, sulfadiazine, sulfapyridine
long acting: sulfadoxine
oral, nonabsorbable: sulfasalazine. used to treat UC, IBD
Topical: ophth: sodium sulfacetamide
burns: silver sulfadiazine, mafenide

Question 2

Sulfonamides MOA

Answer 2

interferes with bacterial growth by inhibiting bacterial folic acid sythesis thru competative antagonism of para-amino benzoic acid

Question 3

Sulfonamides SOA

Answer 3

pneumocyctis jiroveci (cause of PCP pneu in AIDS pts)
Nocardia

Question 4

Sulfonamides clinical use

Answer 4

Sulfisoxazole and sulfamethoxazole: UTI, nocardiosis

adjust in renal failure

Question 5

Sulfonamides ADRs

Answer 5

GI n/v/d, c. diff enterocolitis
hypersensitivity: rash, Stevens Johnson Syndrome (sloughing skin, life threatening) photosensitivity, urticaria
hematologic
crystalluria

Question 6

Sulfonamides Dose

Answer 6

sulfisoxazole 1gm qid up to 6x/d
sulfamethoxaole 1 g bid
never used by iteself

Question 7

trimethoprim

Answer 7

often used with sulfonamides.
Clinical use: use alone if sulfa allergy, pneumocystisis carinii pneumonia (with dapsone)
generally well tolerated

Question 8

Trimethoprim-sulfamethoxazole

Answer 8

TMP-SMX or co-trimoxazole
1:5 ratio
usually bactericidal
MRSA, listeria monosytogens, e coli, proteus mriabilis, vibrio, h flu, neisseria
Clinical Use: UTI, URI, pneumocystis jiroveci pneu, toxoplasmosis, SSTI–MRSA, shigellosis, salm, traves diarrhea–2nd line
Renal failure: prolonged half life

Question 9

sulfadiazine with pyrimethamine use

Answer 9

acute toxoplasmosis

Question 10

sulfadoxine and pyrimethamine use

Answer 10

malaria