UPDATE 1-US FDA calls for curbs on some cough, cold products

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WASHINGTON, May 25 (Reuters) - The U.S. Food and Drug Administration on Friday ordered an end to the manufacturing and distribution of certain cough and cold medicines containing the expectorant guaifenesin that are sold without the agency's approval.

The products, made by about 20 drugmakers and mostly available by prescription, are time-released and are used to clear mucus from the lungs. But they never underwent the FDA's formal clearance process, the agency said.

Only two such medicines -- Mucinex and Humibid made by Adams Respiratory Therapeutics Inc. ARXT.O and available over the counter -- have U.S. approval.

Some of the other, unapproved products are sold under the names Guaifenex, Crantex and Amibid, the FDA said. It was not immediately clear who made those brands.

Adams shares were up more nearly 10 percent at $44 in afternoon trading on the Nasdaq after the FDA announcement.

Deborah Autor, head of the FDA's Center for Drug Evaluation and Research Office of Compliance, said the agency is trying to clear the unapproved products from pharmacies because it cannot assure that they are safe or work.

"These firms have bypassed FDA's rigorous approval process. FDA has not determined that they are safe and effective as formulated and manufactured," Autor told reporters.

Unapproved products can reach the market in a variety of ways, including being sold before FDA regulations are put in place. The FDA has said doctors continue to prescribe the usually older medicines because they are unaware they lack approval.

The agency warned 66 makers of products that contained only guaifenesin in 2002, but Autor said Friday's action includes combination products.

The FDA said manufacturers have until Aug. 27 to stop making the medicines and until November 25 to stop shipping them. About 65 companies help distribute the products, Autor said.

Companies that do not comply could face product seizures and injunctions, she said, adding the medicines could still remain on pharmacy shelves for sometime. (Additional reporting by Varsha Tickoo in Bangalore)