In the wake of Australia’s decision to pull Novartis’ COX-2 inhibitor Prexige from the market, healthcare regulators in Europe and elsewhere are imposing restrictions on the drug over fears that it may cause serious liver damage.

Novartis, following consultation with the UK’s Medicines and Healthcare products Regulatory Agency and other European regulators, is writing to health professionals to inform them of new restrictions on the prescribing of Prexige (lumiracoxib), which is used to treat painful symptoms of osteoarthritis of the knee and hip. The MHRA noted the new measures include regular liver monitoring for patients taking Prexige and insisting that it should not be prescribed to patients with current liver disease or those thought to be at possible risk.

The UK is the reference member state for the EU's mutual recognition procedure for Prexige and the MHRA’s actions will be more or less followed across the continent.

The agency noted that to date, it has received 16 reports of suspected adverse reactions to lumiracoxib in the UK since March 2006 and one of these was a liver reaction which recovered after treatment was stopped. It added that “it is important to note that not all adverse drug reactions are reported and therefore these data cannot be used to calculate the frequency of adverse reactions” but equally any such report “does not necessarily mean that it was caused by the drug”.

Most of 11 case reports of severe liver reactions reported worldwide to date relate to doses higher than the 100mg of Prexige used in the European Union and the MHRA went on to say that the balance of risks and benefits of the drug will be further evaluated by European regulatory authorities in September. Until then, “prescribers are reminded to use lumiracoxib for the shortest period necessary to control symptoms, and not to exceed the recommended 100mg daily dose”.

Novartis has previously noted that most of the cases in Australia involved patients being prescribed 200mg doses of the drug and one was for 400mg. However, “the 100mg dose of Prexige, which is the recommended dose worldwide for treatment of osteoarthritis, has not been associated with an unexpected incidence of liver-related side effects”.

Concern about Prexige, and particularly a high dose of the drug, is not confined to Australia and Europe. Health Canada is conducting a review of the drug and New Zealand has withdrawn the supply of 200mg and 400mg Prexige tablets.