The European Medicines Agency (EMA) has started a review of the risk of dosing errors with methotrexate medicines. When used for inflammatory diseases, such as arthritis and psoriasis, methotrexate is taken once a week whereas for some types of cancer, the dose is higher and the medicine is used more frequently. Mistakes have led to some patients incorrectly receiving a dose every day instead of every week. As a result, patients have received too much of the medicine, with serious consequences in some cases.