Aug. 18, 2006
 
HEALTH: New Decongestant Ingredient Concerns Pharmacists
 
By Lee Bowman
Scripps Howard News Service
 
Pharmacists at the University of Florida are warning that a popular new ingredient in over-the-counter decongestants is likely to be ineffective at the dose approved by the federal Food and Drug Administration.
 
The drug, phenylephrine, is rapidly making its way into many oral cold and allergy medicines to replace pseudoephedrine, a decongestant whose sale is being more tightly regulated because the drug can be used to manufacture methamphetamine.
 
By the end of next month, all medicines containing pseudoephedrine are going to have to be moved behind drugstore counters to control sales.
 
But in a recent peer-reviewed letter to the Journal of Allergy and Clinical Immunology, University of Florida pharmacists Leslie Hendeles and Randy Hatton, warn that phenylephrine is poorly absorbed into the bloodstream and will not work as well as medicines containing pseudoephedrine.
 
"When it is ingested, it becomes inactivated somewhere between the gut and the liver," said Hendeles, an FDA consultant who served on the agency's pulmonary advisory committee for six years. "More research needs to be done to determine whether higher doses can be effective and safe."
 
With products containing phenylephrine filling the shelves, Hendeles recommends that people seeking relief from congestion try nose sprays with the ingredient instead, especially for stuffiness from a cold lasting less than a week.
 
But he cautioned that people trying to treat congestion from allergies that last longer than a week should avoid phenylephrine products, because a "rebound effect" from it can actually make congestion worse.
 
"Consumers in that situation should go that extra step and get pseudoephedrine from behind the counter," Hendeles said.
 
In 1976, FDA considered a 10-milligram dose of phenylephrine safe and effective for relieving congestion, allowing companies to use the ingredient without conducting clinical studies.
 
Hendeles and Hatton write that the drug is not effective at a small dose. They note the FDA cited four positive studies of its effectiveness, two of which were unpublished and sponsored by drug makers. The FDA also noted six tests that found no difference between phenylephrine and a placebo.
 
"They need to do a dose-response study to determine at what higher dose they get both efficacy and safety," Hendeles said.
 
FDA officials overseeing nonprescription drugs say the approval of the drug dose 30 years ago was an open process to which no one objected at the time, but note that any citizen can file a petition asking the agency to reconsider approval if new evidence comes to light.
 
Phenylephrine has been commonly used in nonprescription nasal sprays and in eye and hemorrhoid medicines for years. And because it doesn't have to pass through the digestive system, it is highly effective in those products, but not as an oral remedy.
 
Dr. Miles Weinberger, director of pediatric allergy and pulmonary care at the University of Iowa College of Medicine, said he's shocked at the number of cold and allergy remedy manufacturers switching to an ingredient with such doubtful effectiveness.
 
"They're taking a moderately effective nasal decongestant and replacing it with an ineffective medication," he said.
 
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