Sulfonamides/TMP-SFZ

Question 1

Therapeutic class

Answer 1

antibacterial

Question 2

pharmacologic class

Answer 2

folic acid inhibitor, sulfonamide

Question 3

pregnancy category

Answer 3

C

Question 4

mechanisms of action

Answer 4

inhibit bacterial metabolism of folic acid; each drug inhibits a separate enzyme in the metabolic pathway

Question 5

indications

Answer 5

infections caused by susceptible organisms; UTIs

Question 6

contraindications

Answer 6

hypersensitivity to sulfites, sulfonamides or chemically related agents
folate deficiency anemia
severe renal impairment
hyperkalemia

Question 7

precautions

Answer 7

hepatic impairment

Question 8

drug interactions

Answer 8

may enhance the effects or oral anticoagulants and increase risk of toxicity
diuretics may cause hyperkalemia
may increase hypoglycemic response to sulfonylureas
do not use potassium supplements

Question 9

adverse effects

Answer 9

nausea and vomiting
skin rash
pruritus
fever
photosensitivity

Question 10

serious adverse effects

Answer 10

STEVENS-JOHNSON SYNDROME; anaphylaxis, epidermal necrolysis, agranulcytosis, aplasitc anemia, allergic myocarditis

Question 11

responsibilities

Answer 11

give PO doses w/ full glass of fluid, maintain 2-3L per day; monitor for asthma during IV; monitor lab PT if on warfarin; monitor I&O; older adults at risk for severe adverse reactions

Question 12

teaching

Answer 12

report rash, fever, purpura, sore throat or jaundice; drink 2-3 L/day; report severe or persistent diarrhea w/ fever; no OTC remedies; no breast feeding