A five year study by Yale University, Connecticut, has found a small, but significant risk of haemorrhagic stroke in women taking non-prescription cough and cold medicines, appetite suppressants, and some prescription decongestants containing phenylpropanolamine (PPA).
After hearing the evidence presented by the researchers—who were headed by Dr Walter Kernan, an associate professor of medicine at Yale—an advisory 14 member panel of the US Food and Drug Administration (FDA) voted overwhelmingly to ban phenylpropanolamine in non-prescription decongestants and appetite suppressants.
“It did not meet the burden of proof for safety,” said Dr Eric Brass, the panel chairman, and chairman of the department of medicine at Harbor-UCLA Medical Center in Torrance, California.
Phenylpropanolamine is found in a large number of proprietary medicines, such as Alka-Seltzer Plus Cold Medicine, Contac 12 Hour Cold Capsules, Dexatrim, Dimotapp, Robitussin CF, and Triaminic DM Cold Relief.
The FDA said that six billion doses of medicines containing phenylpropanolamine were sold last year. The FDA has been receiving reports for decades that some patients taking phenylpropanolamine experienced haemorrhagic stroke, which is relatively rare compared with ischaemic stroke. Since 1969 it has received 44 such reports.
The Yale study compared 702 patients aged 18 to 49 years who had experienced haemorrhagic stroke with 1376 patients in a control group. The study and control groups contained too few men for conclusions to be drawn.
But among women the risk of haemorrhagic stroke was found to be as much as 15 times higher in those who had taken appetite suppressants in the three days before the stroke. Among women using medicines containing phenylpropanolamine for the first time, the risk of haemorrhagic stroke was three times higher than for other women.
Epidemiologists who spoke on behalf of the Consumer Healthcare Products Association, a trade group, criticised the case-control study, which has not yet been published, as flawed in design and inconclusive, with too few subjects to draw meaningful conclusions.
“It's not a very robust test of hypothesis,” said Dr Charles Hennekens, a former professor of medicine at Harvard University, who was hired by the industry to review the findings. “It was unfortunate that people accepted this like it was the gospel.”