FDA Approves Once-a-Week Prozac

From the WebMD Archives

Feb. 27, 2001 (Washington) -- Federal regulators may have granted Prozac a new lease on life just mere months before the aging antidepressant is scheduled to face generic competition.

The FDA approved Tuesday a weekly version of the blockbuster medication for the long-term treatment of depression. Prozac is now the only prescription antidepressant with once-a-week dosing.

Eli Lilly, the maker of Prozac, says the longer-acting form of the drug was designed to offer an easier treatment regimen for patients on long-term therapy.

"It was actually developed for patients that have the symptoms under control but still require treatment to prevent a relapse," Anne Griffin, a Lilly spokesperson, tells WebMD.

Experts agree that this type of ongoing maintenance therapy is needed.

"A serious misconception about depression treatment is that as soon as symptoms go away, the patient is cured," explains Noel Gardner, MD, associate professor of psychiatry at the University of Utah in Salt Lake City. "In fact, a high percentage of patients who stop taking their medication too soon ... may experience a relapse within two months."

The once-a-week version of Prozac, Gardner tells WebMD, may help patients avoid that relapse by making it easier to maintain needed treatment without the burden of taking a pill every day.

"Certainly, we think for some patients it will be more convenient," he says.

But the approval is still sure to raise a few eyebrows.

In August 2000, a federal judge ruled that a generic drugmaker, Barr Laboratories of Ponoma, N.Y., could begin making and marketing their own version of Prozac in 2001. The ruling ended a four-year long legal battle, during which Lilly attempted to extend patent protection for the drug through 2003.

Generic drugs often sell for half the price of the brand-name equivalent, but as a newly approved drug, the weekly version of Prozac will now enjoy patent protection until 2017.

That could spell at least a partial financial boon to the brand-name drugmaker. Though sales of Prozac have declined over the past two years, thanks in large part to increased competition from Pfizer's Zoloft and SmithKline's Paxil, sales of Prozac still topped $2.5 billion in 2000.


As a result, the company warned Wall Street analysts in 2000 that it could suffer a significant decline in earnings if could not maintain its sales of Prozac through the release of new formulations and the approval of new uses.

In July 2000, the company made partial headway when the FDA approved Prozac under the name Sarafem for the treatment of premenstrual dysphoric disorder, a condition characterized by intense mood and physical symptoms following a woman's period. However, Prozac almost simultaneously lost its status as America's No. 1 antidepressant, falling behind both Zoloft and Paxil.

Still, experts say Prozac can continue playing a large role in the treatment of depression.

"In my opinion, there is very little substantial difference between any of these drugs," Leon Hoffman, MD, director of the Parent Child Center at the New York Psychoanalytic Society, tells WebMD.

The good news for consumers is that they are at least due for a price break. According to Griffin, the once-weekly version will sell for about 5% less than the daily 20-mg daily version, which costs approximately $2.63 a day.

Consumers and physicians will also have almost immediate access to the new formulation, Griffin says. The drug is expected to be available by early March, she tells WebMD.

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