Hypersensitivity (allergic) reactions are seen rarely with Elocta and these include: swelling of the face, rash, hives, tightness of the chest and difficulty breathing, burning and stinging at the injection site, chills, flushing, itching over the whole body, headache, low blood pressure, lethargy, nausea, restlessness, and a fast heartbeat. In some cases these reactions can become severe.

There is also a risk with factor VIII medicines that some patients will develop inhibitors (antibodies) against factor VIII, causing the medicine to stop working and resulting in a loss of bleeding control.

For the full list of side effects and restrictions of Elocta, see the package leaflet.