Drug interactions
Rifampin + Tolbutamide
Severity: Moderate
Rifampin 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
Rifampin induces hepatic metabolism of tolbutamide and lowers its concentrations, which can cause loss of glycemic control. Effect develops over days to weeks and reverses after rifampin is stopped.
What this interaction means in plain words
Rifampin 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
Induction of CYP2C9 and other hepatic enzymes increases tolbutamide clearance.
What to do
Monitor blood glucose and increase the tolbutamide dose if needed, or switch to another agent. Reduce the dose again if rifampin is discontinued.
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 Rifampin with Tolbutamide?
MediHelp rates the interaction as moderate. Rifampin 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. Rifampin induces hepatic metabolism of tolbutamide and lowers its concentrations, which can cause loss of glycemic control. Effect develops over days to weeks and reverses after rifampin is stopped.
How serious is the interaction between Rifampin 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 and increase the tolbutamide dose if needed, or switch to another agent. Reduce the dose again if rifampin is discontinued.
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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