What are the side effects of natalizumab?
• In the original clinical trials for Tysabri, 3 of 3000 patients taking Tysabri combined with another drug developed a very serious brain infection called Progressive Multifocal Leukoencephalopathy (PML). Two of those three patients with PML died. The exact risk of developing PML using Tysabri alone (not in combination with other drugs) is unknown at this time; however, the risk is assumed to be around one in 1,000. Patients on Tysabri may be at risk for other serious infections, such as pneumonia, as well. • Urinary tract or upper respiratory tract infections • Headaches, fatigue, depression, stomach aches, joint pain, diarrhea • Rare allergic reactions that can be mild or serious. Mild allergic reactions do not require treatment. Severe allergic reactions require immediate and intensive medical treatment.
