Drug interactions
Chlorpropamide + Ketoconazole
Severity: Moderate
Chlorpropamide and Ketoconazole: 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
Ketoconazole may raise chlorpropamide levels and enhance its glucose-lowering effect, causing hypoglycemia that can be prolonged given chlorpropamide's long half-life. Ketoconazole itself has also been associated with glycemic changes.
What this interaction means in plain words
Chlorpropamide and Ketoconazole 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.
Chlorpropamide belongs to Endocrine; Ketoconazole belongs to Anti Fungals.
Why it happens
Ketoconazole is thought to inhibit CYP2C9-mediated metabolism of the sulfonylurea.
What to do
Monitor blood glucose closely when starting or stopping ketoconazole and reduce the chlordiazepoxide-free sulfonylurea dose if hypoglycemia occurs. Educate the patient on 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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Other interactions of Chlorpropamide
Frequently asked questions
Can I take Chlorpropamide with Ketoconazole?
MediHelp rates the interaction as moderate. Chlorpropamide and Ketoconazole 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. Ketoconazole may raise chlorpropamide levels and enhance its glucose-lowering effect, causing hypoglycemia that can be prolonged given chlorpropamide's long half-life. Ketoconazole itself has also been associated with glycemic changes.
How serious is the interaction between Chlorpropamide and Ketoconazole?
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 ketoconazole and reduce the chlordiazepoxide-free sulfonylurea dose if hypoglycemia occurs. Educate the patient on hypoglycemia symptoms.
What other medicines interact with Ketoconazole?
MediHelp also lists interactions of Ketoconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Ketoconazole page.
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