Drug interactions
Mefenamic acid + Tolbutamide
Severity: Moderate
Mefenamic acid 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
Mefenamic acid may enhance the glucose-lowering effect of tolbutamide and cause hypoglycemia. Tolbutamide is cleared by CYP2C9, which NSAIDs of this class also use.
What this interaction means in plain words
Mefenamic acid 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.
Mefenamic acid belongs to Musculoskeletal; Tolbutamide belongs to Endocrine.
Why it happens
Competition for CYP2C9 metabolism and plasma protein binding sites may raise free tolbutamide levels.
What to do
Monitor blood glucose closely when starting or stopping mefenamic acid and reduce the tolbutamide dose if hypoglycemia occurs.
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 Mefenamic acid
- Ketorolac intranasal + Mefenamic acid Contraindicated
- Ketorolac + Mefenamic acid Contraindicated
- Aceclofenac + Mefenamic acid Major
- Acemetacin + Mefenamic acid Major
- Acetylsalicylic acid + Mefenamic acid Major
- Alteplase + Mefenamic acid Major
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 Mefenamic acid with Tolbutamide?
MediHelp rates the interaction as moderate. Mefenamic acid 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. Mefenamic acid may enhance the glucose-lowering effect of tolbutamide and cause hypoglycemia. Tolbutamide is cleared by CYP2C9, which NSAIDs of this class also use.
How serious is the interaction between Mefenamic acid 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 when starting or stopping mefenamic acid and reduce the tolbutamide dose if hypoglycemia occurs.
What other medicines interact with Mefenamic acid?
MediHelp also lists interactions of Mefenamic acid with, for example, Ketorolac intranasal, Ketorolac, Aceclofenac. The full list is on the Mefenamic acid page.
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