The US Food and Drug Administration has called for all manufacturers of non-steroidal anti-inflammatory drugs to amend the labelling of their products to warn of the potential that their use can increase cardiovascular events.

The sweeping changes affect not only the COX-2 inhibitors – including Pfizer’s Celebrex (celecoxib) – but also 18 non-selective NSAIDs, including ibuprofen, diclofenac, naproxen and ketoprofen. The changes also apply to Merck & Co’s Vioxx (rofecoxib) and Pfizer’s Bextra (valdecoxib), which have been withdrawn from the market because of the cardiovascular risk issue [[01/10/04a]], [[08/04/05a]].

The FDA is also asking manufacturers of over-the-counter NSAIDs to revise their labelling to provide more specific information about the potential cardiovascular effects and to tighten up existing warnings about gastrointestinal risks. It particularly wants the labels to emphasise that NSAID doses should be limited and the duration of treatment kept short.

The template issued by the FDA for the boxed warning reads as follow: “NSAIDs may cause an increased risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal. This risk may increase with duration of use. Patients with cardiovascular disease or risk factors for cardiovascular disease may be at greater risk.”

The move follows the publication of a study in the British Medical Journal, which found that NSAID use was associated with a 24% to 55% increase in risk of suffering a heart attack [[13/06/05a]], although its findings were immediately questioned by the Pharmaceutical Society of Great Britain.