Drug interactions
Levonorgestrel + Mavacamten
Severity: Major
Levonorgestrel and Mavacamten: major 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
Mavacamten may lower exposure to progestins and ethinyl estradiol through enzyme induction, potentially leading to contraceptive failure or breakthrough bleeding. The effect may persist after mavacamten is stopped.
What this interaction means in plain words
Levonorgestrel and Mavacamten can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Levonorgestrel belongs to Endocrine; Mavacamten belongs to Cardiovascular.
Why it happens
Mavacamten is reported to induce CYP3A4, increasing progestin metabolism.
What to do
Add or switch to a non-hormonal contraceptive method during therapy and for several months after the last mavacamten dose, as per labeling.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Levonorgestrel and Mavacamten, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Levonorgestrel
Other interactions of Mavacamten
- Apalutamide + Mavacamten Contraindicated
- Carbamazepine + Mavacamten Contraindicated
- Clarithromycin + Mavacamten Contraindicated
- Dexlansoprazole + Mavacamten Contraindicated
- Efavirenz + Mavacamten Contraindicated
- Enzalutamide + Mavacamten Contraindicated
Frequently asked questions
Can I take Levonorgestrel with Mavacamten?
MediHelp rates the interaction as major. Levonorgestrel and Mavacamten can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Mavacamten may lower exposure to progestins and ethinyl estradiol through enzyme induction, potentially leading to contraceptive failure or breakthrough bleeding. The effect may persist after mavacamten is stopped.
How serious is the interaction between Levonorgestrel and Mavacamten?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Add or switch to a non-hormonal contraceptive method during therapy and for several months after the last mavacamten dose, as per labeling.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
