Counterfeiting of medicines in the UK is rare, with a supply chain of licensed and regulated manufacturers, wholesalers and retailers, mainly high street pharmacies. The ABPI said that it was good to see the medicine's authentic manufacturer, Lilly ICOS UK Ltd, working closely with the Government's regulatory authority not only in ensuring the batches of counterfeits are withdrawn but also, where appropriate, in identifying how the items entered the supply chain.

"The integrity of the supply chain is of utmost importance to the pharmaceutical industry, and it is equally important that the manufacturers' original packaging is not interfered with," said Dr Richard Barker, Director General of the ABPI.

"This incident highlights the need for the greatest vigilance and scrutiny, especially when medicines are introduced into the system other than from their original manufacturers. The best protection against counterfeiting is to ensure that the products bought are those supplied by the authentic manufacturer.

"Only then can the industry feel confident that its products are reaching patients in the same condition as they left the factory, and that patients are receiving medication that they can trust absolutely."