Drug interactions
Sulfisoxazole + Tolbutamide
Severity: Moderate
Sulfisoxazole and Tolbutamide: moderate interaction.
Last updated
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
Sulfisoxazole can markedly enhance the effect of tolbutamide, and hypoglycemia has been reported. Risk is greater with renal impairment or reduced food intake.
What this interaction means in plain words
Sulfisoxazole and Tolbutamide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Sulfisoxazole displaces tolbutamide from plasma proteins and inhibits its CYP2C9 metabolism.
What to do
Monitor blood glucose closely and lower the tolbutamide dose if needed during sulfisoxazole therapy.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Tolbutamide
- Glyburide-metformin + Tolbutamide Major
- Insulin degludec-liraglutide + Tolbutamide Major
- Aceclofenac + Tolbutamide Moderate
- Acemetacin + Tolbutamide Moderate
- Acetylsalicylic acid + Tolbutamide Moderate
- Albiglutide + Tolbutamide Moderate
Frequently asked questions
Can I take Sulfisoxazole with Tolbutamide?
MediHelp rates the interaction as moderate. Sulfisoxazole and Tolbutamide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Sulfisoxazole can markedly enhance the effect of tolbutamide, and hypoglycemia has been reported. Risk is greater with renal impairment or reduced food intake.
How serious is the interaction between Sulfisoxazole and Tolbutamide?
MediHelp rates it moderate, 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 lower the tolbutamide dose if needed during sulfisoxazole therapy.
What other medicines interact with Tolbutamide?
MediHelp also lists interactions of Tolbutamide with, for example, Glyburide-metformin, Insulin degludec-liraglutide, Aceclofenac. The full list is on the Tolbutamide page.
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