Drug interactions
Posaconazole + Tolbutamide
Severity: Moderate
Posaconazole 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
Posaconazole may increase tolbutamide levels and its glucose-lowering effect. Tolbutamide is cleared mainly by CYP2C9, so the effect is less certain than with fluconazole, but hypoglycemia is possible.
What this interaction means in plain words
Posaconazole 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.
Posaconazole belongs to Anti Fungals; Tolbutamide belongs to Endocrine.
Why it happens
Possible inhibition of CYP-mediated tolbutamide metabolism by posaconazole.
What to do
Monitor blood glucose closely during co-therapy 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 Posaconazole
- Artemether + Posaconazole Contraindicated
- Avanafil + Posaconazole Contraindicated
- Cobimetinib + Posaconazole Contraindicated
- Conivaptan + Posaconazole Contraindicated
- Dihydroergotamine intranasal + Posaconazole Contraindicated
- Dihydroergotamine + Posaconazole 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 Posaconazole with Tolbutamide?
MediHelp rates the interaction as moderate. Posaconazole 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. Posaconazole may increase tolbutamide levels and its glucose-lowering effect. Tolbutamide is cleared mainly by CYP2C9, so the effect is less certain than with fluconazole, but hypoglycemia is possible.
How serious is the interaction between Posaconazole 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 during co-therapy and reduce the tolbutamide dose if hypoglycemia occurs.
What other medicines interact with Posaconazole?
MediHelp also lists interactions of Posaconazole with, for example, Artemether, Avanafil, Cobimetinib. The full list is on the Posaconazole page.
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