The FDA issued a public health advisory early in November about the risk of hemorrhagic stroke (bleeding into the brain) from taking medications containing the ingredient phenylpropanolamine (PPA). It is used in a large number of over-the-counter and prescription cough-cold preparations as a decongestant and in diet pills. The FDA has asked drug companies to discontinue marketing their products that contain the ingredient, and many retailers immediately removed such products from their shelves.

lifeclinic.com clinical advisory board member Dr. L. Michael Prisant noted that PPA is a vasoconstrictor and raises blood pressure in people who take it. 'People who are taking antihypertensive medications and have their blood pressure under control can lose that control if they take medications containing PPA,' he said. 'Other common ingredients such as pseudoephedrine and phenylephrine are also vasoconstrictors and may similarly adversely affect people with high blood pressure. These agents can also cause angina and heart attacks.' He advises his patients at the Hypertension Unit of the Medical College of Georgia to avoid taking such preparations.

FDA acted after a study conducted by researchers at the Yale University School of Medicine found an association between PPA and stroke in women. The increased risk of stroke was detected in women using the drug for weight control and for nasal congestion. The stroke usually occurred in the 3 days after starting use of the medication. Men may also be at risk; there were too few men in the study group to enable a valid prediction.

PPA is one of the most commonly used non-prescription medications, with billions of doses consumed in the US every year. Since 1979, there have been 30 published reports of bleeding into the brain following ingestion of a PPA-containing product. Most cases involved PPA in diet pills, with at least 5 cases in people who had taken a cough-cold medication. Those most affected were young people, particularly women, 17 to 45 years old.

The Yale study, called the Hemorrhagic Stroke Project, was undertaken to evaluate those reports. It studied 702 people who had had a stroke and 1376 control subjects. When the characteristics of the two groups were examined, it was found that the people who had strokes following use of PPA were twice as likely to have hypertension as those who did not: 39% of the stroke victims had high blood pressure, compared to 20% of those in the control group. Hypertension is, of course, an independent risk factor for stroke.

Sources:

• Horwitz RI, Brass LM, Kernan WN, Viscoli CM. Phenylpropanolamine and risk of hemorrhagic stroke. Final Report, May 10, 2000.
• FDA issues public health warning on phenylpropanolamine. FDA Talk Paper, Nov. 6, 2000.