Current evidence says 10-milligram dose works, but advisers urge study of higher doses
FRIDAY, Dec. 14 (HealthDay News) -- A decongestant in many of the most popular over-the-counter cold medicines appears effective at its current dosage, U.S. health experts ruled Friday. But they also urged that more studies be done.
The panel of advisers to the U.S. Food and Drug Administration had heard day-long testimony on whether OTC cold medicines containing the decongestant phenylephrine really provide nasal congestion relief.
The medicines, which include Sudafed PE, Robitussin Night Relief Syrup, Tylenol Sinus and DayQuil capsules, all contain phenylephrine in a 10-milligram dose.
On Friday, members of the FDA's Nonprescription Drugs Advisory Committee voted 11-1 that existing evidence seems to support the effectiveness of phenylephrine at that dose.
In a second vote, 9-3, the panel urged further study of phenylephrine's safety and effectiveness at higher doses, including 25 milligrams, the Associated Press reported.
"What we know from the studies completed to date is that the 10- milligram dose is probably effective, but it's murky," said Yale University Professor Mary Tinetti, who chaired the panel.
The FDA is not required to follow the recommendations of its advisory panels, but it usually does.
Industry experts applauded the panel's vote.
Linda A. Suydam, president of the Consumer Healthcare Products Association, said in a prepared statement that the vote "reaffirms the results of numerous scientific studies and decades of consumer experience. CHPA and the leading makers of OTC cough, cold, and allergy medicines containing phenylephrine are committed to adding to the existing body of evidence currently supporting the safety and efficacy of phenylephrine."
She added, "Our goal is to continue to provide consumers with safe and effective therapies, and we are committed to working with FDA to ensure that the scientific data further supports this goal."
CHPA's members include Bayer, GlaxoSmithKline, Perrigo and most other makers of over-the-counter medicines, according to the AP.
The issue had been brought to the FDA by University of Florida researchers whose review of 14 studies on phenylephrine suggested that pill and syrup versions of these medicines offered users no real relief. The researchers had petitioned the FDA to investigate the matter and also examine the possibility of requiring higher doses that would work.
Drug companies have recently turned to phenylephrine as a replacement for another decongestant, pseudoephedrine, to comply with a 2006 U.S. law requiring that products containing pseudoephedrine be sold from behind the counter. The law was designed to prevent these medications from being bought in bulk and turned into methamphetamine.
On the academics' side, according to the AP, was drug maker Schering-Plough, which had decided not to reformulate its Claritin line of decongestants, which contain pseudoephedrine.
"If you have a stuffy nose, and you take an over-the-counter product containing phenylephrine, you will still not be able to breathe through your nose after you take it. That's the bottom line," Leslie Hendeles, a professor of pharmacy and pediatrics at the University of Florida, contended before the advisers met.
Hendeles had led the review, which was published in the July 2006 issue of the Journal of Allergy and Clinical Immunology, and he had petitioned the FDA to boost the maximum allowable dose of phenylephrine in oral decongestants to 25 milligrams, which he believes may be more effective.
"There needs to be a dose-response study where you look a 10-, 25- and 50-milligram doses and determine what dose would give you a relief of your stuffy nose without side effects," he said.
But one expert worried that boosting doses of phenylephrine might come at a price.
"No medicine ever has been shown beyond the shadow of a doubt to be effective for the common cold," noted Dr. Bruce Barrett, an associate professor of family medicine at the University of Wisconsin in Madison. "The main problem with decongestants is that they stimulate the heart and increase blood pressure."
Barrett is concerned that if the dose of phenylephrine is too high, it will result in increased blood pressure and other cardiac side effects.
"If applied to tens of thousands of people, you will get cardiac arrhythmias, some of them fatal," Barrett said. "The FDA may need to see studies of tens of thousands of people to see the severity of side effects, and the drug companies may not have the money to do that."
For more about colds and flu, visit the American Lung Association.
SOURCES: Leslie Hendeles, Pharm.D., professor, pharmacy and pediatrics, University of Florida, Gainesville; Bruce Barrett, M.D., Ph.D., associate professor, family medicine, University of Wisconsin, Madison; Dec. 14, 2007, statement, Consumer Healthcare Products Association; Associated Press
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