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Alosetron and Itraconazole Interaction

Drug interaction information between Alosetron and Itraconazole.

Alosetron and Itraconazole have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Alosetron and Itraconazole. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.

Drug A

Alosetron

5-HT3 Antagonist (IBS-D)

Drug B

Itraconazole

Azole Antifungal

How They Interact

Itraconazole may block the liver enzymes that break down alosetron, which could lead to higher levels of the drug in your body.

What To Do

Use this combination with caution and talk to your doctor about any new or worsening side effects.

FDA Label Information

Coadministration of alosetron and strong CYP3A4 inhibitors such as clarithromycin, telithromycin, protease inhibitors, voriconazole, and itraconazole has not been evaluated but should be undertaken with caution because of similar potential drug interactions.

Frequently Asked Questions

Can I take Alosetron and Itraconazole together?

This is a moderate interaction. Use this combination with caution and talk to your doctor about any new or worsening side effects.

How serious is the interaction between Alosetron and Itraconazole?

This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.

Why do Alosetron and Itraconazole interact?

Itraconazole may block the liver enzymes that break down alosetron, which could lead to higher levels of the drug in your body.

Understanding the Alosetron and Itraconazole Interaction

FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Alosetron belongs to the 5-HT3 Antagonist (IBS-D) class and Itraconazole belongs to the Azole Antifungal class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Itraconazole may block the liver enzymes that break down alosetron, which could lead to higher levels of the drug in your body. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.

Context around a specific patient determines real-world impact. Alosetron has 12 total documented interactions on file in this dataset, and Itraconazole has 116. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Use this combination with caution and talk to your doctor about any new or worsening side effects. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.

An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Alosetron or Itraconazole based on a web page, speak with your prescriber or pharmacist before making any change.

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.