The US Food and Drug Administration (FDA) will require stronger warnings in the prescribing information for the class of drugs known as TNF blockers.

The warnings will highlight the increased risk of cancer in children and adolescents who receive the drugs to treat juvenile rheumatoid arthritis, Crohn’s disease and other inflammatory diseases.

The FDA will require an updated boxed warning on the drug and will also be working with manufacturers to explore new ways to further define the risk of cancer to young users.

The action is based on the completion of investigation, announced in 2008, which showed an increase in the risk of cancer after an average 30 months of treatment in reports of children and adolescents treated with TNF-blockers in the US.

TNF blockers target and neutralise tumour necrosis factor-alpha (TNF-a), a protein which, when overproduced in the body due to chronic inflammatory diseases, can cause inflammation and damage to bones, cartilage and tissue.