Drug interactions
Efavirenz + Progesterone
Severity: Moderate
Efavirenz and Progesterone: 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
Efavirenz induces CYP3A4 and may reduce progesterone exposure. Reduced levels may weaken endometrial protection or luteal support, and reduce contraceptive progestin efficacy.
What this interaction means in plain words
Efavirenz and Progesterone 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.
Efavirenz belongs to Anti Virals; Progesterone belongs to Endocrine.
Why it happens
Efavirenz induces CYP3A4, increasing progesterone metabolism.
What to do
Monitor for loss of progestogenic effect such as breakthrough bleeding, and adjust the dose if needed. Use an additional or alternative contraceptive method when contraception is the goal.
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 Progesterone
Other interactions of Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Efavirenz with Progesterone?
MediHelp rates the interaction as moderate. Efavirenz and Progesterone 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. Efavirenz induces CYP3A4 and may reduce progesterone exposure. Reduced levels may weaken endometrial protection or luteal support, and reduce contraceptive progestin efficacy.
How serious is the interaction between Efavirenz and Progesterone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for loss of progestogenic effect such as breakthrough bleeding, and adjust the dose if needed. Use an additional or alternative contraceptive method when contraception is the goal.
What other medicines interact with Progesterone?
MediHelp also lists interactions of Progesterone with, for example, Apalutamide, Carbamazepine, Enzalutamide. The full list is on the Progesterone page.
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