Drug interactions
Clarithromycin + Tolbutamide
Severity: Moderate
Clarithromycin 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
Clarithromycin may raise tolbutamide exposure and enhance its glucose-lowering effect, and hypoglycemia has been reported with macrolides and sulfonylureas. The effect is variable and typically manageable but can be significant in elderly patients or those with renal impairment.
What this interaction means in plain words
Clarithromycin 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.
Clarithromycin belongs to Anti Bacterial; Tolbutamide belongs to Endocrine.
Why it happens
Possible inhibition of CYP2C9-mediated tolbutamide metabolism and/or protein binding displacement; the mechanism is not firmly established.
What to do
Monitor blood glucose closely when clarithromycin is started or stopped and reduce the tolbutamide dose if hypoglycemia occurs. Counsel patients on recognizing 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 Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine 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 Clarithromycin with Tolbutamide?
MediHelp rates the interaction as moderate. Clarithromycin 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. Clarithromycin may raise tolbutamide exposure and enhance its glucose-lowering effect, and hypoglycemia has been reported with macrolides and sulfonylureas. The effect is variable and typically manageable but can be significant in elderly patients or those with renal impairment.
How serious is the interaction between Clarithromycin 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 clarithromycin is started or stopped and reduce the tolbutamide dose if hypoglycemia occurs. Counsel patients on recognizing hypoglycemia symptoms.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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