US regulator knocks AstraZeneca's hopes for Prilosec drug

AstraZeneca, the pharmaceutical group, has suffered a major setback in its attempts to slow falling sales of its blockbuster Prilosec drug, after US regulators questioned the anti-ulcerant's suitability as an over-the-counter (OTC) medicine.

AstraZeneca, the pharmaceutical group, has suffered a major setback in its attempts to slow falling sales of its blockbuster Prilosec drug, after US regulators questioned the anti-ulcerant's suitability as an over-the-counter (OTC) medicine.

An advisory panel to the US Food and Drug Administration said that it could not recommend Prilosec, which is marketed as Losec in Europe, as an OTC heartburn drug until it had more data on the effects of its long-term use. It was also concerned that frequent use of Prilosec might mask more serious gastric conditions and prevent people seeking medical attention. The FDA rarely ignores the panel's advice.

While the FDA in its weekend comments said it believed Prilosec could be a safe prescription drug, the question mark over possible OTC approval increases the likelihood of its sales falling sharply when it loses patent protection in the US next year. Prilosec's sales were $5.91bn (£4bn) in 1999.

The FDA threw out Wellcome's application to make Zovirax an OTC treatment for genital herpes in 1995, after the panel voiced the same concerns about the risk of the drug masking serious medical conditions.

Transforming a prescription drugs into OTC products is a method pharmaceutical firms use to extend the sales life of drugs that have come off patent. AstraZeneca wants to market Prilosec as a drug that prevents heartburn as well as treats it - a claim that only so-called proton pump inhibitor (PPI) drugs, available on prescription, can make. Prilosec is already seeing sales decline in Europe where Losec is coming off patent. Only Sweden has approved the drug for OTC distribution.

Peter Cartwright, an analyst at Williams de Bröe, said: "Prilosec didn't make it [to OTC status] at first attempt, and plenty of drugs don't. But this isn't a case of failing to tick a box one week and being able to come back and tick it the next."