Drug interactions
Levonorgestrel + Ritonavir
Severity: Moderate
Levonorgestrel 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 alters the metabolism of hormonal contraceptives and can change progestin exposure, with the risk of reduced contraceptive reliability or increased adverse effects. Effects depend on the formulation and duration of ritonavir use.
What this interaction means in plain words
Levonorgestrel 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.
Levonorgestrel belongs to Endocrine; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir inhibits CYP3A4 while also inducing other metabolic pathways such as glucuronidation, giving variable progestin exposure.
What to do
Use an additional or alternative non-hormonal method with oral contraceptives; a levonorgestrel intrauterine system is a reasonable choice.
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 Levonorgestrel
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 Levonorgestrel with Ritonavir?
MediHelp rates the interaction as moderate. Levonorgestrel 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 alters the metabolism of hormonal contraceptives and can change progestin exposure, with the risk of reduced contraceptive reliability or increased adverse effects. Effects depend on the formulation and duration of ritonavir use.
How serious is the interaction between Levonorgestrel 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: Use an additional or alternative non-hormonal method with oral contraceptives; a levonorgestrel intrauterine system is a reasonable choice.
What other medicines interact with Levonorgestrel?
MediHelp also lists interactions of Levonorgestrel with, for example, Amobarbital, Apalutamide, Belzutifan. The full list is on the Levonorgestrel page.
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