Question

A patient has a prescription for a sulfa drug as treatment for a UTI. She is also taking an oral contraceptive, an oral sulfonylurea antidiabetic drug, and phenytoin for a history of seizures. Which drug may pose a potential serious interaction with the sulfa drug?

A.The oral contraceptive
B.The oral antidiabetic drug
C.The phenytoin
D.All of these

Answer 1

All of the listed drugs may have potential serious interactions with a sulfa drug. Sulfa drugs can decrease the effectiveness of oral contraceptives, enhance the hypoglycemic effect of sulfonylureas, and increase serum concentrations of phenytoin.

Step-by-step explanation:

Regarding the question asking which drug may pose a potential serious interaction with a sulfa drug being taken by a patient for a urinary tract infection (UTI), while also taking an oral contraceptive, an oral sulfonylurea antidiabetic drug, and phenytoin for a history of seizures, the answer is D. All of these. Sulfa drugs can decrease the effectiveness of oral contraceptives, potentially leading to an increased risk of unintended pregnancy. Furthermore, sulfa drugs may potentiate the hypoglycemic effects of sulfonylureas, increasing the patient’s risk of hypoglycemia. Lastly, sulfa drugs can increase the serum concentration of phenytoin, which may heighten the risk of toxicity from this drug.