Although
Tysabri® (
natalizumab) can be an effective treatment for
Crohn's disease and
multiple sclerosis (
MS), it is not an appropriate medicine for everyone. For example, this prescription medicine can increase the risk for a serious brain infection called progressive multifocal leukoencephalopathy (PML). Tysabri is more likely to cause this infection if you also take medications that weaken your immune system.
PML can cause severe disability and even death. Contact your healthcare provider right away if you experience any signs of PML, such as:
- Weakness on one side of the body
- Vision problems
- Confusion
- Personality changes.
If you develop PML during treatment, you will need to stop using Tysabri.