Drug interactions
Estrogens, conjugated + Ritonavir
Severity: Moderate
Estrogens, conjugated and Ritonavir: 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
Ritonavir is a potent CYP3A4 inhibitor but also induces some estrogen conjugation pathways, so net estrogen exposure is unpredictable. Patients may have either excess estrogenic effects or reduced efficacy.
What this interaction means in plain words
Estrogens, conjugated and Ritonavir 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.
Estrogens, conjugated belongs to Musculoskeletal; Ritonavir belongs to Anti Virals.
Why it happens
CYP3A4 inhibition by ritonavir combined with induction of glucuronidation, giving variable estrogen exposure.
What to do
Monitor symptom control, bleeding and estrogenic adverse effects and adjust the estrogen dose according to clinical response.
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 Estrogens, conjugated
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Estrogens, conjugated with Ritonavir?
MediHelp rates the interaction as moderate. Estrogens, conjugated and Ritonavir 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. Ritonavir is a potent CYP3A4 inhibitor but also induces some estrogen conjugation pathways, so net estrogen exposure is unpredictable. Patients may have either excess estrogenic effects or reduced efficacy.
How serious is the interaction between Estrogens, conjugated and Ritonavir?
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 symptom control, bleeding and estrogenic adverse effects and adjust the estrogen dose according to clinical response.
What other medicines interact with Estrogens, conjugated?
MediHelp also lists interactions of Estrogens, conjugated with, for example, Carbamazepine, Itraconazole, Ketoconazole. The full list is on the Estrogens, conjugated page.
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