Drug interactions
Etrasimod + Natalizumab
Severity: Major
Etrasimod and Natalizumab: 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
Both drugs reduce lymphocyte-mediated immunity, so combining them may raise the risk of serious infection. Etrasimod has not been studied with other immunomodulators and its effect on lymphocyte counts persists for weeks after stopping.
What this interaction means in plain words
Etrasimod and Natalizumab 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.
Etrasimod belongs to Gastrointestinal Tract; Natalizumab belongs to Gastrointestinal Tract.
Why it happens
Additive immunosuppression from S1P receptor modulation (lymphocyte sequestration) and blockade of alpha-4 integrin lymphocyte trafficking.
What to do
Avoid coadministration, including in the weeks after stopping etrasimod. If switching, check lymphocyte counts and monitor for infection, including PML signs.
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 Natalizumab
- Natalizumab + Vedolizumab Contraindicated
- Axicabtagene ciloleucel + Natalizumab Major
- Baricitinib + Natalizumab Major
- Belatacept + Natalizumab Major
- Brexucabtagene autoleucel + Natalizumab Major
- Cabazitaxel + Natalizumab Major
Other interactions of Etrasimod
- Abatacept + Etrasimod Major
- Amiodarone + Etrasimod Major
- Anagrelide + Etrasimod Major
- Anakinra + Etrasimod Major
- Anti-thymocyte + Etrasimod Major
- Asenapine + Etrasimod Major
Frequently asked questions
Can I take Etrasimod with Natalizumab?
MediHelp rates the interaction as major. Etrasimod and Natalizumab 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. Both drugs reduce lymphocyte-mediated immunity, so combining them may raise the risk of serious infection. Etrasimod has not been studied with other immunomodulators and its effect on lymphocyte counts persists for weeks after stopping.
How serious is the interaction between Etrasimod and Natalizumab?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid coadministration, including in the weeks after stopping etrasimod. If switching, check lymphocyte counts and monitor for infection, including PML signs.
What other medicines interact with Natalizumab?
MediHelp also lists interactions of Natalizumab with, for example, Vedolizumab, Axicabtagene ciloleucel, Baricitinib. The full list is on the Natalizumab page.
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