FDA clears 'generic Prozac' for sale

WASHINGTON (CNN) -- Five pharmaceutical companies received letters from the Food and Drug Administration Thursday granting them the right to sell fluoxetine, the lower-priced generic version of the popular antidepressant Prozac.

The patent on the drug, held by Eli Lilly, expires at midnight.

The five laboratories were given exclusive rights to produce different version of fluoxetine for six months.

Barr Laboratories, which went to court to end the patent, will have exclusive rights to produce 20-mg capsules, which account for $2.2 billion of the current $2.7 billion Prozac market.

Dr. Reddy's Laboratories will produce 40-mg capsules, Teva Pharmaceuticals will produce 20-mg liquid fluoxetine, Geneva Pharmaceuticals will manufacture 10-mg capsules, and Pharmaceutical Resources will make 10- and 20-mg tablets.

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Barr said some pharmacies may receive shipments of the drug Friday.

The 90-mg weekly dosage of Prozac remains exclusive to Lilly, under a "new chemical exclusivity."

Serafem, a version of fluoxetine for treatment of severe PMS, remains exclusive to Eli Lilly until 2007.

The patent on Prozac was to have expired February 2, but the FDA extended it six months because Lilly was conducting research on using the drug in children.

Prozac is not approved by the FDA for children but it is widely prescribed off-label for childhood depression, obsessive compulsive disorders, anxiety, and some eating disorders.

The extension expired Thursday. An appeals court last month ruled against Lilly's request for another extension. Lilly has 90 days to petition the U.S. Supreme Court to hear arguments for continued exclusive rights to the drug.

The company said loss of the patent will not harm the company's bottom line.

"We've been preparing for this day for a long time. We feel we are well prepared," Lilly spokesman Ed West said in a statement. "We have a clearly articulated strategy for success in the future that has yielded the industry's strongest pipeline of new products, 10 of which will be introduced over the next two to three years. So, the future looks very, very bright."

West said Lilly plans to introduce two other antidepressants next year.

Barr would not say how much it will charge for the 20-mg capsules. Lilly's brand-name version costs $2.50 per capsule. Observers say that after the six-month exclusivity, competition from other manufacturers could drop the price to as low as 25 cents a pill.

Prozac, patented in 1977 and launched in 1987, is one of the biggest-selling drugs in history.

According to the Generic Pharmaceutical Association, it was the fourth-largest selling drug in the United States last year and is one of the biggest-selling drugs to go off patent.

If Lilly decides to petition the Supreme Court, Barr would have 30 days to file an opposition brief and the Supreme Court would have another 10 days to decide whether to hear the case.

Lilly acknowledged it is unlikely the nation's high court would overturn the appellate court's ruling.