Drug interactions
Megestrol + Warfarin
Severity: Moderate
Megestrol and Warfarin: 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
Increases in INR and bleeding have been reported in patients on warfarin who start megestrol. The reports are limited, and the effect varies between patients.
What this interaction means in plain words
Megestrol and Warfarin 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.
Megestrol belongs to Oncology; Warfarin belongs to Cardiovascular.
Why it happens
The mechanism is not established; altered warfarin metabolism or protein binding has been proposed.
What to do
Check INR within a week of starting or stopping megestrol and adjust the warfarin dose accordingly.
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 Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Other interactions of Megestrol
- Dofetilide + Megestrol Contraindicated
- Insulin degludec / insulin aspart + Megestrol Moderate
- Insulin degludec-insulin aspart + Megestrol Moderate
- Insulin degludec-liraglutide + Megestrol Moderate
- Insulin degludec + Megestrol Moderate
- Insulin inhaled + Megestrol Moderate
Frequently asked questions
Can I take Megestrol with Warfarin?
MediHelp rates the interaction as moderate. Megestrol and Warfarin 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. Increases in INR and bleeding have been reported in patients on warfarin who start megestrol. The reports are limited, and the effect varies between patients.
How serious is the interaction between Megestrol and Warfarin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check INR within a week of starting or stopping megestrol and adjust the warfarin dose accordingly.
What other medicines interact with Warfarin?
MediHelp also lists interactions of Warfarin with, for example, Defibrotide, Ketorolac, Abciximab. The full list is on the Warfarin page.
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