This article is from the WebMD Medical News Archive

Coming Soon: Generic Antidepressants

Drug Makers Ready New, Improved Pills as Generics Near Pharmacies

By Daniel DeNoon WebMD Medical News

Reviewed By Michael Smith, MD on Wednesday, September 03, 2003

Sept. 3, 2003 -- Cheaper antidepressants are on the way. But will you want to buy them?

That depends. As the patents on several antidepressants near their expiration dates, manufacturers of generic antidepressants are gearing up. The stakes are high: By 2007, Americans will spend $13.5 billion on the drugs. And the rest of the world will spend billions more.

A generic version of Prozac has been available since 2001. This year the FDA approved a generic version of Paxil. It will be on pharmacy shelves no later than 2005. Generic Zoloft is coming in mid-2006. And soon to come are generic versions of Wellbutrin SR and Celexa.

But brand-name drug makers bet you won't want them. They hope you stick with the brand names. And they hope you'll switch -- but not to generic antidepressants. They hope you'll want the "new, improved" versions of brand-name drugs such as Wellbutrin XL, Paxil CR, and Lexapro, the new version of Celexa.

Will Patients Follow the Follow-Ons?

They're called "follow-on" products in the drug biz. They've been changed just enough to allow drug makers to keep the patent -- and the higher price. How significant are the improvements?

The new drugs are "incrementally better," says Michael J. Owens, PhD, associate professor of psychiatry and associate director of the neuropsychopharmacology lab at Atlanta's Emory University School of Medicine.

"If costs were not an issue, the new drugs would be a first choice," Owens tells WebMD. "But when you take the cost/benefit ratio into consideration, it becomes more nebulous where a doctor should go."

So far, there have been two types of improvements. One is to make new extended-release versions of the drugs. Paxil, for example, becomes Paxil CR.

The other idea is to make a new drug out of the active three-dimensional form of the old drug, separating it from less active forms. Mixed-form Celexa, for example, became single-form Lexapro.

Fewer Side Effects

What makes the extended-release antidepressants better is that they last longer between doses. Once-a-day drugs are a lot easier to take. That makes it easier for patients to follow doctors' orders and get maximum benefit from their medicine.

That's not all. The longer-lasting formulations go lower in the digestive tract before they dissolve. This cuts down on some of the drugs' worst side effects, says Mark I. Levy, MD, a private-practice psychiatrist and assistant professor of psychiatry at the University of California, San Francisco.

"Effexor XR is the most dramatic example," Levy tells WebMD. "People who took the original version of the drug had a lot of gastrointestinal symptoms, like nausea. The extended-release version eliminated that.

"And there are different extended-release technologies. Take Prozac Weekly, for example. The weekly version [uses strategies] that result in the drug working differently. ... Now with the weekly version, there are fewer side effects such as decreased sexual desire."

That Ole' Brand Magic

The FDA requires that generic drugs have to reach blood levels of at least 80% of the brand name drug. But the generic drugs use different inactive ingredients. That may or may not make a difference. Levy says some of his patients had problems with some generic versions of Prozac.

"When Prozac went off patent, I had a lot of patients come in saying, 'Maybe I have Prozac poop-out.' In every case it was because they were switched by their HMOs to generic fluoxetine," Levy says. "I put them back on name-brand Prozac, and the drug's effect was restored. There is a lot of difference in terms of who the generic manufacturer is. Teva Pharmaceuticals, for example, made good fluoxetine. But milligram for milligram, with generics you don't necessarily get the same bang for the buck."

Even so, much of the effect may be what doctors call brand magic. It's a version of the placebo effect, which is especially strong in the treatment of depression. That's been a big problem for clinical trials of antidepressants, because patients treated with placebos -- identical-looking pills with no active ingredient -- get a lot less depressed.

Page: 1 | 2    Next: Coming Soon: Generic Antidepressants

Print Friendly Version          Email a Friend