Drug interactions
Ethinyl estradiol-drospirenone + Nirmatrelvir
Severity: Moderate
Ethinyl estradiol-drospirenone 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 is given with ritonavir, which can lower ethinyl estradiol exposure, so contraceptive efficacy may be reduced during and shortly after the short course. Nirmatrelvir itself has little direct effect. Unintended pregnancy is the main concern.
What this interaction means in plain words
Ethinyl estradiol-drospirenone 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-drospirenone belongs to Endocrine; Nirmatrelvir belongs to Anti Virals.
Why it happens
Ritonavir booster is thought to induce ethinyl estradiol metabolism (e.g., glucuronidation or CYP1A2/2C9), lowering estrogen levels.
What to do
Advise an additional non-hormonal contraceptive method during treatment and for the remainder of the cycle after stopping. Continue the pill as scheduled.
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-drospirenone
- Ethinyl estradiol-drospirenone + Fezolinetant Contraindicated
- Ethinyl estradiol-drospirenone + Ombitasvir / paritaprevir / ritonavir Contraindicated
- Ethinyl estradiol-drospirenone + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-drospirenone + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-drospirenone Major
- Amobarbital + Ethinyl estradiol-drospirenone 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-drospirenone with Nirmatrelvir?
MediHelp rates the interaction as moderate. Ethinyl estradiol-drospirenone 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 is given with ritonavir, which can lower ethinyl estradiol exposure, so contraceptive efficacy may be reduced during and shortly after the short course. Nirmatrelvir itself has little direct effect. Unintended pregnancy is the main concern.
How serious is the interaction between Ethinyl estradiol-drospirenone 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 during treatment and for the remainder of the cycle after stopping. Continue the pill as scheduled.
What other medicines interact with Ethinyl estradiol-drospirenone?
MediHelp also lists interactions of Ethinyl estradiol-drospirenone with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir, Ombitasvir / paritaprevir / ritonavir and dasabuvir. The full list is on the Ethinyl estradiol-drospirenone page.
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