Drug interactions
Gemfibrozil + Tolbutamide
Severity: Moderate
Gemfibrozil 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
Gemfibrozil may increase the hypoglycemic effect of tolbutamide. Tolbutamide is a CYP2C9 substrate, and gemfibrozil may reduce its clearance and displace it from protein binding. Hypoglycemia may be more likely in patients with low albumin.
What this interaction means in plain words
Gemfibrozil 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.
Gemfibrozil belongs to Cardiovascular; Tolbutamide belongs to Endocrine.
Why it happens
Possible CYP2C9 inhibition and protein-binding displacement, with additive glucose lowering.
What to do
Monitor blood glucose after starting or stopping gemfibrozil. 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 Gemfibrozil
- Daprodustat + Gemfibrozil Contraindicated
- Elagolix + Gemfibrozil Contraindicated
- Gemfibrozil + Mavacamten Contraindicated
- Gemfibrozil + Metformin-repaglinide Contraindicated
- Gemfibrozil + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Gemfibrozil + Repaglinide Contraindicated
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 Gemfibrozil with Tolbutamide?
MediHelp rates the interaction as moderate. Gemfibrozil 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. Gemfibrozil may increase the hypoglycemic effect of tolbutamide. Tolbutamide is a CYP2C9 substrate, and gemfibrozil may reduce its clearance and displace it from protein binding. Hypoglycemia may be more likely in patients with low albumin.
How serious is the interaction between Gemfibrozil 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 after starting or stopping gemfibrozil. Reduce the tolbutamide dose if hypoglycemia occurs.
What other medicines interact with Gemfibrozil?
MediHelp also lists interactions of Gemfibrozil with, for example, Daprodustat, Elagolix, Mavacamten. The full list is on the Gemfibrozil page.
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