This page contains brief details about the drug , it's indication, dosage & administaration, mechanism of action, related brands with strength, warnings and common side effects.

Background and Date of Approval

Natalizumab was initially approved by the United States Food and Drug Administration (FDA) November 23, 2004,

Mechanism of Action of undefined

Natalizumab is a monoclonal antibody that works by targeting a protein called α4-integrin on certain immune cells. By binding to α4-integrin, it prevents these immune cells from crossing the blood-brain barrier in multiple sclerosis or migrating into the gut lining in Crohn's disease. This action reduces inflammation and helps protect the central nervous system in MS, leading to fewer relapses and slowed disease progression. Overall, its mechanism of action modulates the immune response, providing therapeutic benefits in the treatment of multiple sclerosis and Crohn's disease.

Uses of undefined

Natalizumab is a monoclonal antibody used primarily for treating multiple sclerosis (MS) and moderate to severe Crohn's disease. 

undefined Drug administaration and Dosage available

Natalizumab should be taken exactly as prescribed by a healthcare professional. The route of administration for this medication is intravenous (IV) infusion. This means that the medication is delivered directly into the bloodstream through a vein. This medication is not available in oral form or as a subcutaneous injection.

Warnings, Precautions and Side Effects of undefined


Natalizumab increases the risk of PML, a rare and potentially fatal brain infection. Serious infusion reactions, including anaphylaxis, can occur during or shortly after the infusion. It may cause liver injury, as indicated by elevated liver enzyme levels. This medication can increase the risk of serious infections, including opportunistic infections and reactivation of latent infections. Live vaccines should not be administered to patients receiving this medication due to potential interference with the immune response.


Patients require close monitoring for symptoms, and treatment should be discontinued if PML is suspected. Patients require observation during and after the infusion. Regular liver function monitoring may be required. Patients should discuss all medical conditions and medications with their healthcare provider before starting Natalizumab to ensure safe and appropriate treatment. 

Side Effects

Natalizumab may cause various side effects. Common side effects include headache, fatigue, and upper respiratory tract infections. However, there are serious side effects, such as progressive multifocal leukoencephalopathy (PML), a rare but potentially fatal brain infection, and hypersensitivity reactions during or after infusion. Liver damage and an increased risk of infections are also possible. 

Word Of Advice

For Natalizumab, safe use is close monitoring for signs of progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection, as well as hypersensitivity reactions during or after infusion. Regular liver function tests should be performed to detect any liver damage. Patients should be vigilant for signs of infections, and concomitant use with other immunomodulatory medications should be carefully considered. Prior screening for hepatitis B virus (HBV) is recommended, and live vaccines should not be administered during treatment. Pregnant or breastfeeding individuals should consult their healthcare provider before starting or continuing this medication. It is essential to discuss all medical conditions and medications with the healthcare provider to ensure the safe and appropriate use of this medication and to address any potential risks.

Frequently Asked Question


  1. Biogen Netherlands BV, Electronic medicines compendium (emc), [Revised on 15th July 2022] [Accessed on 30th July 2023],
  2. Elan Pharmaceuticals, Inc, US Food and Drug Administration, [Revised on  08/2017][ Accessed on 30th July 2023],
  3. Rachel Branstadter, Ilana Katz Sand; The use of natalizumab for multiple sclerosis; Neuropsychiatrist Disease and Treatment; Published on June 2017; Accessed on 30th July 2023;


The drug information on this page is not a substitute for medical advice, it is meant for educational purposes only. For further details, consult your doctor about your medical condition to know if you can receive this treatment