Drug interactions
Lorlatinib + Norethindrone
Severity: Major
Lorlatinib and Norethindrone: major interaction.
Last updated Sources: US FDA label
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 CYP3A4 and may lower norethindrone exposure, so hormonal contraception may be less reliable. Lorlatinib labeling specifically advises on nonhormonal contraception.
What this interaction means in plain words
Lorlatinib and Norethindrone 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.
Why it happens
CYP3A4 induction accelerates progestin metabolism.
What to do
Use an effective nonhormonal contraceptive method during lorlatinib therapy and for a period after discontinuation.
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?
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References
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 Lorlatinib with Norethindrone?
MediHelp rates the interaction as major. Lorlatinib and Norethindrone 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 CYP3A4 and may lower norethindrone exposure, so hormonal contraception may be less reliable. Lorlatinib labeling specifically advises on nonhormonal contraception.
How serious is the interaction between Lorlatinib and Norethindrone?
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 an effective nonhormonal contraceptive method during lorlatinib therapy and for a period after discontinuation.
What other medicines interact with Lorlatinib?
MediHelp also lists interactions of Lorlatinib with, for example, Amobarbital, Apalutamide, Butabarbital. The full list is on the Lorlatinib page.
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