Drug interactions
Lopinavir + Norethisterone
Severity: Moderate
Lopinavir and Norethisterone: 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
Lopinavir is co-formulated with ritonavir, which affects hormonal contraceptive exposure variably, so contraceptive reliability and tolerability can change. Norethisterone levels may rise or the contraceptive effect may be unreliable.
What this interaction means in plain words
Lopinavir and Norethisterone 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.
Lopinavir belongs to Anti Virals; Norethisterone belongs to Endocrine.
Why it happens
Ritonavir-boosted lopinavir inhibits CYP3A4 while also inducing glucuronidation, giving variable effects on norethisterone clearance.
What to do
Advise an additional or alternative non-hormonal contraceptive method. Monitor for adverse effects and breakthrough bleeding.
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 Lopinavir
- Alfuzosin + Lopinavir Contraindicated
- Avanafil + Lopinavir Contraindicated
- Cisapride + Lopinavir Contraindicated
- Dronedarone + Lopinavir Contraindicated
- Eletriptan + Lopinavir Contraindicated
- Eplerenone + Lopinavir Contraindicated
Frequently asked questions
Can I take Lopinavir with Norethisterone?
MediHelp rates the interaction as moderate. Lopinavir and Norethisterone 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. Lopinavir is co-formulated with ritonavir, which affects hormonal contraceptive exposure variably, so contraceptive reliability and tolerability can change. Norethisterone levels may rise or the contraceptive effect may be unreliable.
How serious is the interaction between Lopinavir and Norethisterone?
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 or alternative non-hormonal contraceptive method. Monitor for adverse effects and breakthrough bleeding.
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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