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Drug interactions

Melphalan + Natalizumab

Severity: Major

Melphalan and Natalizumab: 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

Melphalan is a myelosuppressive alkylating agent that causes significant immunosuppression. Combined with natalizumab, there is a greater risk of serious and opportunistic infections, including PML.

What this interaction means in plain words

Melphalan 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.

Melphalan belongs to Oncology; Natalizumab belongs to Gastrointestinal Tract.

Evidence level: Low

Why it happens

Additive immunosuppression from cytotoxic myelosuppression and blockade of lymphocyte trafficking.

What to do

Avoid concurrent use where possible. If it is unavoidable, monitor blood counts and screen for infection and neurological symptoms.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Melphalan with Natalizumab?

MediHelp rates the interaction as major. Melphalan 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. Melphalan is a myelosuppressive alkylating agent that causes significant immunosuppression. Combined with natalizumab, there is a greater risk of serious and opportunistic infections, including PML.

How serious is the interaction between Melphalan 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 concurrent use where possible. If it is unavoidable, monitor blood counts and screen for infection and neurological symptoms.

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.

Full monographs, dosing and an interaction checker in the MediHelp app

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