Drug interactions
Levonorgestrel + Lorlatinib
Severity: Major
Levonorgestrel and Lorlatinib: 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
Lorlatinib induces CYP3A and may reduce levonorgestrel exposure, potentially weakening oral or emergency contraception. Intrauterine delivery is less affected because of mainly local action.
What this interaction means in plain words
Levonorgestrel and Lorlatinib 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; Lorlatinib belongs to Oncology.
Why it happens
CYP3A4 induction by lorlatinib increases levonorgestrel metabolism.
What to do
Use a nonhormonal method or a levonorgestrel IUD plus condoms during lorlatinib therapy. For emergency contraception, prefer a copper IUD or consider a higher levonorgestrel dose per local guidance.
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 Lorlatinib, 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 14 days on the web. No card needed.
Other interactions of Levonorgestrel
Other interactions of Lorlatinib
- Amobarbital + Lorlatinib Contraindicated
- Apalutamide + Lorlatinib Contraindicated
- Butabarbital + Lorlatinib Contraindicated
- Carbamazepine + Lorlatinib Contraindicated
- Enzalutamide + Lorlatinib Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
Frequently asked questions
Can I take Levonorgestrel with Lorlatinib?
MediHelp rates the interaction as major. Levonorgestrel and Lorlatinib 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. Lorlatinib induces CYP3A and may reduce levonorgestrel exposure, potentially weakening oral or emergency contraception. Intrauterine delivery is less affected because of mainly local action.
How serious is the interaction between Levonorgestrel and Lorlatinib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a nonhormonal method or a levonorgestrel IUD plus condoms during lorlatinib therapy. For emergency contraception, prefer a copper IUD or consider a higher levonorgestrel dose per local guidance.
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.
