Drug interactions
Ethinyl estradiol-levonorgestrel + Nirmatrelvir
Severity: Moderate
Ethinyl estradiol-levonorgestrel and Nirmatrelvir: 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
Nirmatrelvir given with ritonavir may reduce ethinyl estradiol exposure during and shortly after the short treatment course. Contraceptive protection may be slightly reduced.
What this interaction means in plain words
Ethinyl estradiol-levonorgestrel and Nirmatrelvir 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; Nirmatrelvir belongs to Anti Virals.
Why it happens
Ritonavir probably induces enzymes such as glucuronidation and CYP pathways; the exact mechanism is not established.
What to do
Advise an additional non-hormonal contraceptive method for the remainder of the cycle after the course. Counsel the patient regarding missed-dose guidance.
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 Nirmatrelvir
- Alfuzosin + Nirmatrelvir Contraindicated
- Amiodarone + Nirmatrelvir Contraindicated
- Apalutamide + Nirmatrelvir Contraindicated
- Carbamazepine + Nirmatrelvir Contraindicated
- Colchicine + Nirmatrelvir Contraindicated
- Dronedarone + Nirmatrelvir Contraindicated
Frequently asked questions
Can I take Ethinyl estradiol-levonorgestrel with Nirmatrelvir?
MediHelp rates the interaction as moderate. Ethinyl estradiol-levonorgestrel and Nirmatrelvir 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. Nirmatrelvir given with ritonavir may reduce ethinyl estradiol exposure during and shortly after the short treatment course. Contraceptive protection may be slightly reduced.
How serious is the interaction between Ethinyl estradiol-levonorgestrel and Nirmatrelvir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise an additional non-hormonal contraceptive method for the remainder of the cycle after the course. Counsel the patient regarding missed-dose guidance.
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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