Drug interactions
Ethinyl estradiol-levonorgestrel + Lonafarnib
Severity: Moderate
Ethinyl estradiol-levonorgestrel and Lonafarnib: 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
Lonafarnib is a sensitive CYP3A substrate, and ethinyl estradiol is a weak CYP3A inhibitor that may modestly raise lonafarnib levels. Lonafarnib may also inhibit CYP3A and affect hormone exposure, and its QT effect is uncertain.
What this interaction means in plain words
Ethinyl estradiol-levonorgestrel and Lonafarnib 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.
Ethinyl estradiol-levonorgestrel belongs to Endocrine; Lonafarnib belongs to Miscellaneous.
Why it happens
Weak CYP3A4 inhibition by ethinyl estradiol increasing lonafarnib exposure.
What to do
If coadministration is needed, keep lonafarnib at the starting dose rather than escalating, and monitor for gastrointestinal toxicity and for palpitations or syncope. Consider ECG monitoring.
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 Ethinyl estradiol-levonorgestrel
- Ethinyl estradiol-levonorgestrel + Fezolinetant Contraindicated
- Ethinyl estradiol-levonorgestrel + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-levonorgestrel + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-levonorgestrel Major
- Amobarbital + Ethinyl estradiol-levonorgestrel Major
- Anastrozole + Ethinyl estradiol-levonorgestrel Major
Other interactions of Lonafarnib
- Alfuzosin + Lonafarnib Contraindicated
- Amobarbital + Lonafarnib Contraindicated
- Apalutamide + Lonafarnib Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Carbamazepine + Lonafarnib Contraindicated
- Clarithromycin + Lonafarnib Contraindicated
Frequently asked questions
Can I take Ethinyl estradiol-levonorgestrel with Lonafarnib?
MediHelp rates the interaction as moderate. Ethinyl estradiol-levonorgestrel and Lonafarnib 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. Lonafarnib is a sensitive CYP3A substrate, and ethinyl estradiol is a weak CYP3A inhibitor that may modestly raise lonafarnib levels. Lonafarnib may also inhibit CYP3A and affect hormone exposure, and its QT effect is uncertain.
How serious is the interaction between Ethinyl estradiol-levonorgestrel and Lonafarnib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: If coadministration is needed, keep lonafarnib at the starting dose rather than escalating, and monitor for gastrointestinal toxicity and for palpitations or syncope. Consider ECG monitoring.
What other medicines interact with Ethinyl estradiol-levonorgestrel?
MediHelp also lists interactions of Ethinyl estradiol-levonorgestrel with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir and dasabuvir, Tranexamic acid. The full list is on the Ethinyl estradiol-levonorgestrel page.
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