Drug interactions
Glyburide + Sulfamethoxazole
Severity: Major
Glyburide and Sulfamethoxazole: major interaction.
Last updated Sources: US FDA label
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Sulfamethoxazole, usually taken as co-trimoxazole, can increase the glucose-lowering effect of glyburide and cause severe hypoglycemia. Risk is higher in older patients and those with renal impairment.
What this interaction means in plain words
Glyburide and Sulfamethoxazole can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Sulfamethoxazole inhibits CYP2C9 metabolism of glyburide and may displace it from plasma proteins.
What to do
Monitor blood glucose closely and reduce the glyburide dose during co-trimoxazole therapy. Consider an alternative antibiotic in high-risk patients.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Glyburide
- Bosentan + Glyburide Contraindicated
- Cholic acid + Glyburide Major
- Ciprofloxacin + Glyburide Major
- Clarithromycin + Glyburide Major
- Fluconazole + Glyburide Major
- Glyburide + Insulin degludec-liraglutide Major
Frequently asked questions
Can I take Glyburide with Sulfamethoxazole?
MediHelp rates the interaction as major. Glyburide and Sulfamethoxazole can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Sulfamethoxazole, usually taken as co-trimoxazole, can increase the glucose-lowering effect of glyburide and cause severe hypoglycemia. Risk is higher in older patients and those with renal impairment.
How serious is the interaction between Glyburide and Sulfamethoxazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood glucose closely and reduce the glyburide dose during co-trimoxazole therapy. Consider an alternative antibiotic in high-risk patients.
What other medicines interact with Glyburide?
MediHelp also lists interactions of Glyburide with, for example, Bosentan, Cholic acid, Ciprofloxacin. The full list is on the Glyburide page.
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