The safety of Tyruko has been evaluated, and on the basis of all the studies carried out the side effects of the medicine are considered to be comparable to those of the reference medicine Tysabri.

For the complete list of side effects and restrictions of Tyruko, see the package leaflet.

Tyruko can increase the risk of infections, including the brain infection PML. PML is a very serious condition that may result in severe disability or death. The risk of PML increases the longer a patient has been receiving Tyruko, especially in patients treated for more than 2 years. The risk is also higher for patients who used medicines that supress the immune system before starting Tyruko, or if the patient has antibodies against the virus that causes PML. If PML is suspected, the doctor must stop treatment until it is certain that the patient does not have this infection.

The most common side effects with Tyruko (which may affect more than 1 in 10 people) are urinary tract infection (infection of the parts of the body that carry urine), nasopharyngitis (inflammation of the nose and throat), headache, dizziness, nausea (feeling sick), joint pain and tiredness.

Patients may develop long-lasting antibodies against natalizumab, which reduces the medicine’s effectiveness.

Tyruko must not be given to patients who have PML or who are at risk of getting an infection, including patients whose immune system is weakened. It must not be given in combination with other disease-modifying medicines or to patients who have cancer (unless it is a skin cancer called basal cell carcinoma).