Patients taking a so-called wonder drug for rheumatoid arthritis have been warned they are three times more likely to develop lymphoma, a cancer of the blood.
The warning came yesterday after Johnson & Johnson said it would be writing to doctors on Monday informing them of the increased risk associated with taking Remicade.
The drug is not being recalled but details of the increased risk will now be included on the information leaflet which comes with it.
Up to 500 Irish patients are believed to be taking the drug.
This is the second time in three months that Remicade's label has been changed to reflect safety concerns that are already listed in the prescribing information for rival drugs in the same class, such as Enbrel and Humira.
They have been among the most successful of all biotechnology drugs.
Dr Oliver Fitzgerald, a consultant rheumatologist and a board member of the Arthritis Foundation of Ireland, said he was not aware of any cases of lymphoma among Irish patients taking the drug.
He said he would like to see the data on which the new warning was based, pointing out that rheumatoid arthritis was itself associated with a higher risk of lymphoma.
Furthermore, he said, rheumatoid arthritis was "a nasty disease" which led to disability and premature death.
"I think you have to balance the risks of the disease against the risks of the treatment itself. If for a patient it offers a good chance of getting back their life, it may be a risk worth taking. But I say that without seeing the latest data."
These latest concerns about an arthritis drug come just a week after Vioxx, an anti-inflammatory used to treat thousands of Irish arthritis sufferers, was withdrawn worldwide after it was found to increase the risk of heart attack and stroke.