Drug interactions
Norethisterone + Topiramate
Severity: Moderate
Norethisterone 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
Topiramate can reduce hormonal contraceptive exposure, mainly at higher doses, and may cause breakthrough bleeding. Contraceptive efficacy may be compromised.
What this interaction means in plain words
Norethisterone 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.
Norethisterone belongs to Endocrine; Topiramate belongs to Central Nervous System.
Why it happens
Topiramate is a dose-dependent weak CYP3A inducer that may increase the metabolism of the progestin.
What to do
Counsel on additional barrier contraception, especially with topiramate doses above about 200 mg daily, and consider a more reliable method such as an IUD. Monitor for breakthrough bleeding as a sign of reduced exposure.
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 Norethisterone
- Acitretin + Norethisterone Contraindicated
- Amobarbital + Norethisterone Major
- Apalutamide + Norethisterone Major
- Belzutifan + Norethisterone Major
- Bosentan + Norethisterone Major
- Brigatinib + Norethisterone Major
Other interactions of Topiramate
Frequently asked questions
Can I take Norethisterone with Topiramate?
MediHelp rates the interaction as moderate. Norethisterone 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. Topiramate can reduce hormonal contraceptive exposure, mainly at higher doses, and may cause breakthrough bleeding. Contraceptive efficacy may be compromised.
How serious is the interaction between Norethisterone 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 on additional barrier contraception, especially with topiramate doses above about 200 mg daily, and consider a more reliable method such as an IUD. Monitor for breakthrough bleeding as a sign of reduced exposure.
What other medicines interact with Norethisterone?
MediHelp also lists interactions of Norethisterone with, for example, Acitretin, Amobarbital, Apalutamide. The full list is on the Norethisterone page.
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