Drug interactions
Felbamate + Levonorgestrel
Severity: Moderate
Felbamate and Levonorgestrel: 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
Felbamate induces CYP3A4 and can lower hormonal contraceptive concentrations, which may lead to contraceptive failure with oral or emergency levonorgestrel. Intrauterine systems act locally and are less affected.
What this interaction means in plain words
Felbamate and Levonorgestrel 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.
Felbamate belongs to Central Nervous System; Levonorgestrel belongs to Endocrine.
Why it happens
Felbamate induces CYP3A4, accelerating levonorgestrel metabolism.
What to do
With oral levonorgestrel, use an additional non-hormonal contraceptive method. An intrauterine system is generally still effective.
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 Levonorgestrel
Other interactions of Felbamate
- Felbamate + Ulipristal Major
- Amisulpride + Felbamate Moderate
- Amitriptyline + Felbamate Moderate
- Apalutamide + Felbamate Moderate
- Asenapine + Felbamate Moderate
- Bosentan + Felbamate Moderate
Frequently asked questions
Can I take Felbamate with Levonorgestrel?
MediHelp rates the interaction as moderate. Felbamate and Levonorgestrel 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. Felbamate induces CYP3A4 and can lower hormonal contraceptive concentrations, which may lead to contraceptive failure with oral or emergency levonorgestrel. Intrauterine systems act locally and are less affected.
How serious is the interaction between Felbamate and Levonorgestrel?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: With oral levonorgestrel, use an additional non-hormonal contraceptive method. An intrauterine system is generally still effective.
What other medicines interact with Levonorgestrel?
MediHelp also lists interactions of Levonorgestrel with, for example, Amobarbital, Apalutamide, Belzutifan. The full list is on the Levonorgestrel page.
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