Drug interactions
Etonogestrel + Topiramate
Severity: Moderate
Etonogestrel and Topiramate: 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
At higher doses topiramate can lower systemic exposure to hormonal contraceptive steroids, which may reduce contraceptive efficacy. Effect with etonogestrel implants or rings is less well characterised but breakthrough bleeding or unintended pregnancy is a concern.
What this interaction means in plain words
Etonogestrel and Topiramate 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.
Etonogestrel belongs to Endocrine; Topiramate belongs to Central Nervous System.
Why it happens
Dose-dependent weak induction of CYP3A4 by topiramate increases progestin metabolism.
What to do
Counsel patients that contraceptive efficacy may be reduced, particularly with topiramate above 200 mg daily, and consider adding a barrier method or a non-hormonal method such as a copper IUD. Report any change in bleeding pattern.
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 Topiramate
Other interactions of Etonogestrel
Frequently asked questions
Can I take Etonogestrel with Topiramate?
MediHelp rates the interaction as moderate. Etonogestrel and Topiramate 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. At higher doses topiramate can lower systemic exposure to hormonal contraceptive steroids, which may reduce contraceptive efficacy. Effect with etonogestrel implants or rings is less well characterised but breakthrough bleeding or unintended pregnancy is a concern.
How serious is the interaction between Etonogestrel and Topiramate?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Counsel patients that contraceptive efficacy may be reduced, particularly with topiramate above 200 mg daily, and consider adding a barrier method or a non-hormonal method such as a copper IUD. Report any change in bleeding pattern.
What other medicines interact with Topiramate?
MediHelp also lists interactions of Topiramate with, for example, Benzhydrocodone / acetaminophen, Buprenorphine long-acting, Buprenorphine subdermal implant. The full list is on the Topiramate page.
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