Drug interactions
Etrasimod + Interferon beta 1b
Severity: Major
Etrasimod and Interferon beta 1b: 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
Etrasimod lowers circulating lymphocyte counts and interferon beta can also affect immune function and cause leukopenia. Combining them could add to immune suppression and raise the risk of infection, and this combination has not been studied. The effect of etrasimod on lymphocytes persists for some weeks after the last dose.
What this interaction means in plain words
Etrasimod and Interferon beta 1b 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; Interferon beta 1b belongs to Central Nervous System.
Why it happens
Additive immunomodulatory effects: etrasimod sequesters lymphocytes via S1P receptor modulation while interferon beta alters immune function and may reduce blood counts.
What to do
Avoid combining these agents, including during the weeks after etrasimod is stopped. If used, monitor the complete blood count and watch closely for signs of infection.
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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Other interactions of Interferon beta 1b
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 Interferon beta 1b?
MediHelp rates the interaction as major. Etrasimod and Interferon beta 1b 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 lowers circulating lymphocyte counts and interferon beta can also affect immune function and cause leukopenia. Combining them could add to immune suppression and raise the risk of infection, and this combination has not been studied. The effect of etrasimod on lymphocytes persists for some weeks after the last dose.
How serious is the interaction between Etrasimod and Interferon beta 1b?
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 combining these agents, including during the weeks after etrasimod is stopped. If used, monitor the complete blood count and watch closely for signs of infection.
What other medicines interact with Interferon beta 1b?
MediHelp also lists interactions of Interferon beta 1b with, for example, Axicabtagene ciloleucel, Brexucabtagene autoleucel, Ciltacabtagene autoleucel. The full list is on the Interferon beta 1b page.
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