Drug interactions
Conjugated estrogens + Lorlatinib
Severity: Moderate
Conjugated estrogens and Lorlatinib: 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
Lorlatinib induces CYP3A and may lower estrogen concentrations, reducing efficacy of hormone therapy. Clinical significance is likely modest for menopausal therapy but could cause recurrence of symptoms or breakthrough bleeding.
What this interaction means in plain words
Conjugated estrogens and Lorlatinib 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.
Why it happens
Lorlatinib induces CYP3A4, accelerating estrogen metabolism.
What to do
Monitor for reduced estrogen effect and adjust the estrogen dose as needed. Where contraception is relied upon, use a non-hormonal method.
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 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 Conjugated estrogens with Lorlatinib?
MediHelp rates the interaction as moderate. Conjugated estrogens and Lorlatinib 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. Lorlatinib induces CYP3A and may lower estrogen concentrations, reducing efficacy of hormone therapy. Clinical significance is likely modest for menopausal therapy but could cause recurrence of symptoms or breakthrough bleeding.
How serious is the interaction between Conjugated estrogens and Lorlatinib?
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 for reduced estrogen effect and adjust the estrogen dose as needed. Where contraception is relied upon, use a non-hormonal method.
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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