Drug interactions
Clarithromycin + Lorlatinib
Severity: Major
Clarithromycin and Lorlatinib: 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
Clarithromycin is a strong CYP3A4 inhibitor and increases lorlatinib exposure, which may worsen hyperlipidemia, CNS effects, and PR interval prolongation. Lorlatinib is itself a CYP3A inducer and may reduce clarithromycin levels, which could lessen antibiotic effect.
What this interaction means in plain words
Clarithromycin 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.
Clarithromycin belongs to Anti Bacterial; Lorlatinib belongs to Oncology.
Why it happens
Strong CYP3A4 inhibition by clarithromycin raises lorlatinib levels, while lorlatinib induces CYP3A.
What to do
Use a non-CYP3A-inhibiting antibiotic if possible. If unavoidable, reduce the lorlatinib dose per labeling and monitor for CNS effects, lipids and ECG changes.
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 Clarithromycin 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 7 days on the web. No card needed.
References
Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
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 Clarithromycin with Lorlatinib?
MediHelp rates the interaction as major. Clarithromycin 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. Clarithromycin is a strong CYP3A4 inhibitor and increases lorlatinib exposure, which may worsen hyperlipidemia, CNS effects, and PR interval prolongation. Lorlatinib is itself a CYP3A inducer and may reduce clarithromycin levels, which could lessen antibiotic effect.
How serious is the interaction between Clarithromycin 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 non-CYP3A-inhibiting antibiotic if possible. If unavoidable, reduce the lorlatinib dose per labeling and monitor for CNS effects, lipids and ECG changes.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin 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.
