A common ingredient of cold and flu remedies has been banned in the US, following a report linking it to an increased risk of haemorrhagic stroke.
On Monday, the US Food and Drug Administration (FDA) told Americans to stop using drugs containing the decongestant phenylpropanolamine (PPA), which is also licensed in the US as an appetite suppressant.
Other countries are now launching inquiries into the safety of the drug. The British Committee on the Safety of Medicines (CSM) will meet on Wednesday 7 November, and its recommendations will be passed to government ministers.
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American chemists have already started withdrawing dozens of over-the-counter cold remedies from their shelves. Brands containing PPA include Contac 400, Benylin Day & Night, Day Nurse and a Vicks cold cure.
But the products are still on sale in Britain. 鈥淲e sell products containing PPA in over 50 countries worldwide, and we are still talking to regulatory bodies in these countries,鈥� says Alan Archer of SmithKline Beecham, which produces Contac 400.
The FDA鈥檚 decision followed the publication of an eight-year study by a team at Yale University. They concluded that PPA causes between 200 and 500 strokes a year in the US in people under 50, most of them young women.
But appetite suppressants, which contain much higher levels of PPA than cold cures, are held to be primarily responsible, and women are much more likely to use appetetite suppressants than men.
鈥淲e are concerned by the results, but we don鈥檛 want people to panic,鈥� says Eoin Redahan of the Stroke Association in London. 鈥淭his study mainly looked at people taking appetite suppressants. And we are talking about a small number of people and a relatively small risk.鈥�
Redahan also points out that the recommended maximum daily dose of PPA is only 100 milligrams in Britain, compared with 150 milligrams in the US.
PPA constricts blood vessels and raises blood pressure. In certain cases, it can cause blood vessels to rupture, leading to bleeding in the brain and stroke.
The Yale study found that people with high blood pressure taking drugs containing PPA were at most risk of haemorrhagic stroke. Warning labels on PPA products in Britain recommend that people with high blood pressure do not take the drug.
鈥淐oncerns about PPA are not new,鈥� says Maria Murray of Britain鈥檚 Department of 午夜福利1000集合. 鈥淚t鈥檚 long been known that this particular class of drug can elevate blood pressure, and that high blood pressure is a risk factor for stroke.
鈥淥ne issue that the CSM will consider is whether the people in the Yale study who suffered strokes would have been warned not to use PPA-containing products in the UK,鈥� she says.
But Redahan points out that half of all people with high blood pressure are not aware of it.
Other medications, including the contraceptive pill, can raise blood pressure. This could be another reason why the Yale team found a much stronger link between PPA and haemorrhagic stroke in young women compared with men, suggests Murray.
The conclusions of tomorrow鈥檚 meeting of the CSM will be passed to the Medicines Control Agency, the British equivalent of the FDA, which will then advise government ministers on whether a ban should be implemented.
In the meantime, 鈥減atients who are concerned should contact their pharmacist who, if necessary, can suggest alternative remedies that do not contain PPA鈥�, Murray says.
The full Yale University report is published in the New England Journal of Medicine, and is available online at .