Drug interactions
Sulfadiazine + Tolbutamide
Severity: Moderate
Sulfadiazine 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
Sulfonamide antibiotics can potentiate sulfonylurea effects and have caused hypoglycemia, sometimes severe. Risk is higher in the elderly and those with renal impairment.
What this interaction means in plain words
Sulfadiazine 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
Sulfadiazine may inhibit CYP2C9-mediated tolbutamide metabolism and displace it from plasma proteins, and sulfonamides may have intrinsic insulin-releasing effects.
What to do
Monitor blood glucose closely during co-therapy, lower the tolbutamide dose if needed, and educate patients on hypoglycemia symptoms.
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 Sulfadiazine with Tolbutamide?
MediHelp rates the interaction as moderate. Sulfadiazine 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. Sulfonamide antibiotics can potentiate sulfonylurea effects and have caused hypoglycemia, sometimes severe. Risk is higher in the elderly and those with renal impairment.
How serious is the interaction between Sulfadiazine 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 during co-therapy, lower the tolbutamide dose if needed, and educate patients on hypoglycemia symptoms.
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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