Natalizumab Side Effects and Warnings

What are the precautions when taking this medicine?

• Serious infections have been reported with use of this medicine. If you have any infection, are taking antibiotics now or in the recent past, or have many infections, talk with healthcare provider.

• If you have liver disease, talk with healthcare provider.

• If you have mental illness, talk with healthcare provider.

• Talk with healthcare provider before receiving any vaccinations. Use with this medicine may either increase the risk of serious infection or make the vaccination less effective.

• Tell dentists, surgeons, and other healthcare providers that you use this medicine.

• Check medicines with healthcare provider. This medicine may not mix well with other medicines.

• Tell healthcare provider if you are pregnant or plan on getting pregnant.

• Tell healthcare provider if you are breast-feeding.

What are some possible side effects of this medicine?

• Risk of infection. Avoid people with infections, colds, or flu.

• Depression.

• Headache.

• Nausea or vomiting. Small frequent meals, frequent mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.

• Belly pain.

• Diarrhea.

• Feeling tired or weak.

• Muscle weakness.

• Joint pain.

• Liver damage can rarely occur.

• Severe allergic reactions can rarely occur.

Reasons to call healthcare provider immediately

• If you suspect an overdose, call your local poison control center or emergency department immediately.

• Signs of a life-threatening reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; fits; or swelling of face, lips, tongue, or throat.

• Signs or symptoms of infection. These include a fever of 100.5 degrees or higher, chills, severe sore throat, ear or sinus pain, cough, increased sputum or change in color, painful urination, mouth sores, wound that will not heal, or anal itching or pain.

• If you are planning to harm yourself or the desire to harm yourself increases.

• Significant change in thinking clearly and logically.

• Sudden change in vision.

• Significant change in balance.

• Dark urine or yellow skin or eyes.

• Feeling extremely tired or weak.

• Severe muscle pain or weakness.

• Any rash.

• No improvement in condition or feeling worse.