Drug interactions
Sulphasalazine + Tolbutamide
Severity: Moderate
Sulphasalazine 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-type drugs such as sulfasalazine may enhance the glucose-lowering effect of tolbutamide, increasing the risk of hypoglycaemia. The effect is probably uncommon but can matter in patients with poor glycaemic stability.
What this interaction means in plain words
Sulphasalazine 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.
Sulphasalazine belongs to Gastrointestinal Tract; Tolbutamide belongs to Endocrine.
Why it happens
Possible protein-binding displacement and/or CYP2C9 metabolism inhibition; not firmly established.
What to do
Monitor blood glucose when starting or stopping sulfasalazine and counsel patients on hypoglycaemia symptoms. Reduce the tolbutamide dose if glucose falls.
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 Sulphasalazine
- Deferiprone + Sulphasalazine Major
- Pexidartinib + Sulphasalazine Major
- Sepiapterin + Sulphasalazine Major
- Acalabrutinib + Sulphasalazine Moderate
- Aceclofenac + Sulphasalazine Moderate
- Asciminib + Sulphasalazine Moderate
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 Sulphasalazine with Tolbutamide?
MediHelp rates the interaction as moderate. Sulphasalazine 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-type drugs such as sulfasalazine may enhance the glucose-lowering effect of tolbutamide, increasing the risk of hypoglycaemia. The effect is probably uncommon but can matter in patients with poor glycaemic stability.
How serious is the interaction between Sulphasalazine 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 when starting or stopping sulfasalazine and counsel patients on hypoglycaemia symptoms. Reduce the tolbutamide dose if glucose falls.
What other medicines interact with Sulphasalazine?
MediHelp also lists interactions of Sulphasalazine with, for example, Deferiprone, Pexidartinib, Sepiapterin. The full list is on the Sulphasalazine page.
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