THE RATE of growth in America’s massive drugs market is set to grind to a halt over the next three years amid mounting safety fears, a leading consultant has revealed.

In a forecast that is closely watched by the pharmaceuticals industry, IMS Health, the industry research firm, is predicting that US sales growth in prescription medicines will flatten out at just 7.5 to 8.5 per cent a year for each of the next three years.

The downbeat outlook comes as IMS said that growth in America, the largest medicines market in the world, plunged to just 8.3 per cent in 2004, the lowest for more than ten years and less than half the rate seen four years ago.

IMS said that safety concerns had weighed heavily on the market in 2004. Sales of Cox-2 inhibitors, the family of painkillers to which Merck’s now-withdrawn Vioxx belongs, were hit particularly hard, falling 9 per cent on the year. Merck pulled Vioxx last September after the drug was linked to thousands of heart attacks and strokes.

Uncertainty over healthcare reforms and competition from generic drugmakers also dented prospects while encouraging advances that saw US regulators approve 31 new compounds during the year — double the approval rate of 2003 — failed to lift the sales numbers.

Paul Wilson, a vice-president of IMS Health, said that new treatments and America’s ageing population would underpin the industry, but that the outlook was not set to “get any easier”.

The forecasts will be closely watched by GlaxoSmithKline, and AstraZeneca, which rely on the US for anything up to half of total drug sales.

Last year, the two companies made total sales of $25.6 billion (£13.5 billion) to American patients.

Paul Diggle, an analyst with Code Securities, last night gave warning that the American market could no longer be relied on to drive industry profits, adding that stalling growth rates would make it harder for big drugmakers to make headway.

The IMS forecasts will make depressing reading for pharmaceuticals companies that are already struggling to cope with a harsher regulatory environment and a sceptical public.

Later this week, the Food and Drug Administration, the US regulator, will meet to decide what action to take over remaining Cox-2 inhibitors still under development. Analysts believe that the agency could demand more tests on patients who might be at particular risk from heart problems.

Other measures under consideration include stricter labelling guidelines, which would require doctors to monitor any patient taking painkillers in the class. A total ban on all Cox-2 inhibitors is considered unlikely.

• President Bush last night said that he would nominate Lester Crawford to serve as commissioner of the Food and Drug Administration. Mr Crawford has served as acting commissioner since Mark McClellan left the agency to head the Centres for Medicare and Medicaid Services.