Sulfamethoxazole and Sulfonylurea: Drug Interaction Guide
Quick answer: This combination requires caution. Sulfamethoxazole and Sulfonylurea can be used together with adjustments and monitoring.
How Sulfamethoxazole interacts with Sulfonylurea
Sulfamethoxazole inhibits CYP2C9, reducing sulfonylurea metabolism (especially glibenclamide and glipizide) and displacing it from albumin, increasing risk of severe prolonged hypoglycemia.
What you should do
Monitor blood glucose frequently during co-treatment, especially in elderly or renal impairment. Consider temporary sulfonylurea dose reduction or alternative antibiotic.
Key facts
Severity
Moderate — caution required
Mechanism
Sulfamethoxazole inhibits CYP2C9, reducing sulfonylurea metabolism (especially glibenclamide and glipizide) and displaci...
Action
Monitor blood glucose frequently during co-treatment, especially in elderly or renal impairment. Consider temporary sulf...
Frequently asked questions
Can I take Sulfamethoxazole and Sulfonylurea together?
With caution. Monitor blood glucose frequently during co-treatment, especially in elderly or renal impairment. Consider temporary sulfonylurea dose reduction or alternative antibiotic.
What is the severity of this interaction?
The interaction between Sulfamethoxazole and Sulfonylurea is classified as Moderate — caution required. Sulfamethoxazole inhibits CYP2C9, reducing sulfonylurea metabolism (especially glibenclamide and glipizide) and displacing it from albumin, increasing risk of severe prolonged hypoglycemia.
What should I do if I'm prescribed both?
Monitor blood glucose frequently during co-treatment, especially in elderly or renal impairment. Consider temporary sulfonylurea dose reduction or alternative antibiotic. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.