Natalizumab

What it is used for

• Highly active relapsing remitting multiple sclerosis

Read our guides:

• Multiple sclerosis

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Natalizumab is not commonly used off-label.

How it works

Natalizumab is a man-made antibody. It stops immune cells crossing from the blood into the brain and spinal cord, where they would cause inflammation and damage.

Side effects

Like all medicines, Natalizumab can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

• headache
• feeling dizzy
• feeling sick
• joint pain
• tiredness
• urine infections
• infusion reactions

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

• new or worsening weakness, clumsiness, problems with speech, vision, thinking or memory, which can be signs of a rare brain infection called PML
• signs of a serious infection
• yellowing of the skin or eyes

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

• You will have regular blood tests for the JC virus and MRI scans to check the risk of PML.
• Carry the patient alert card.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.