Clarinex is new — but is it really better at battling allergy symptoms than its popular predecessor drug, Claritin? Some experts contend their makers' real aim in introducing Clarinex with a flood of ads and discounts is to capture customers before Claritin's patent expires — and cheaper knockoffs muscle in.

It's a strategy that makers of other drugs, faced with looming competition from generic and over-the-counter versions, have used effectively.

And in a time of rising drug expenses, some doctors and pharmacists say it's a strategy we can't afford.

You may have seen those strange new television ads for Clarinex, Schering-Plough's chip-off-the-old-blockbuster replacement for its nonsedating antihistamine pill, Claritin:

An enormous Clarinex pill hurtles toward Earth, a meteor of relief. Cut to Clarinex particles capping histamine receptors in a digitized blood vessel. A voice tells us the drug is the only allergy pill that delivers 24-hour relief from any allergy, anywhere, at any time.

In the background we hear snippets from "Tommy," the Who's rock-opera about a deaf, dumb and blind boy who took a lot of new drugs on his way toward salvation.

Schering-Plough has launched the blitz (with related magazine, newspaper and radio ads) to encourage Claritin users to switch to Clarinex before rival drug makers introduce generic versions of the drug or before Claritin goes over-the-counter, either of which may happen by year's end. The company has even made Clarinex cheaper than Claritin, to expedite the shift to the new drug.

Claritin generated about $3.2 billion in sales worldwide last year, roughly one-third of Schering-Plough's total for pharmaceuticals.

The ads may have you thinking that Clarinex is more effective than Claritin. But doctors interviewed for this story say that's not so.

"It is not any better than Claritin," said Rudy Mueller, a family physician and author of "As Sick as It Gets," a book about, among other topics, how drug makers influence medical practice.

Mueller said there is no science to show that the new drug offers a real advantage over the old one.

Jean Barbey, a physician who is interim director of clinical pharmacology at Georgetown University Medical Center, agreed. The Food and Drug Administration approved Clarinex in December based on studies that proved it worked better than a placebo against allergies. But the tests did not compare the drug head-to-head with Claritin. Without such studies, it's impossible to say whether allergy patients will do better on Clarinex, Barbey said.

In Europe, where Clarinex has been on sale for months, the European Agency for the Evaluation of Medicinal Products tried to make up for that lack of direct comparison by studying trial results for the two drugs. The agency, which clears drugs for sale in European Union countries, concluded that dose per dose, Clarinex is "probably not superior" to Claritin.

British National Health Service pharmacists concluded there was no reason to prefer Clarinex over its predecessor.

New drug more potent

When asked if Clarinex is an improvement over Claritin, Schering-Plough spokesman Bill O'Donnell responds that the new drug, unlike Claritin, is approved to treat indoor allergies — hence the ads' tag about countering allergies that arise "anywhere."

O'Donnell said the company didn't seek FDA approval for indoor allergies for Claritin, but wouldn't speculate how Claritin and Clarinex would do if tested head-to-head for that purpose.

Barbey, once a consultant to Schering-Plough, dismissed the indoor claim as "marketing strategy," but said Clarinex does offer a theoretical advantage.

The body breaks down Claritin into active metabolites, biologically potent chemicals responsible for the drug's effect, he explained. Clarinex is Claritin's most active metabolite, isolated and repackaged as a new drug.

That's why patients who take 10 mg of Claritin can usually take 5 mg of Clarinex, the recommended daily dose. The new drug is more potent. That might be helpful for patients who found that Claritin didn't work well for them.

But because Claritin is converted to Clarinex in the body, most patients get just as much active drug with the 10 mg dose of Claritin as they do with the 5 mg dose of Clarinex, Barbey said.

The Nexium connection

Jennifer Wilson-Norton, director of pharmacy services at the Everett Clinic, a 185-physician group practice in Everett, suspects that Schering-Plough never tested Clarinex against Claritin because the company knew it could not demonstrate a clinically significant difference between the drugs.

"We have looked at the data. We are educating our doctors that Clarinex offers no benefits," she said.

But Wilson-Norton frets that, "As soon as ads hit, patients start asking for the drug," convinced that new means better.

It reminds her of another "new and improved" drug that came out about a year ago and is now advertised constantly on TV — Nexium.

Nexium is AstraZeneca's replacement for its legendarily lucrative heartburn pill, Prilosec. In 2000, Prilosec was the best-selling drug in the nation, with sales topping $4 billion. AstraZeneca is now battling in court to keep generic versions off the market — and battling in the market to drive consumers to Nexium.

Nexium, like Clarinex, is a spinoff of an old blockbuster.

Most drugs are composed of two molecules, mirror images of each other called stereoisomers. AstraZeneca isolated Prilosec's biologically active isomer and repackaged it as a new drug.

In two FDA-reviewed studies, Nexium worked consistently better than Prilosec only when it was used in a higher dose. In a third study, a higher dose of Nexium did not work any better than a lower dose of Prilosec. When the same amounts of drug were used in a fourth study, there was no difference between them.

The studies looked at how quickly the drugs healed erosive esophagitis, a potentially serious condition in which stomach acid eats away at the lining of the esophagus, and how well the drugs prevented heartburn once esophagitis was healed.

The label notes that in three European trials for acid-reflux disease, a far more common cause of heartburn, Nexium offered no significant advantage over Prilosec even at higher doses.

Shortly after the Nexium ads hit, Doug Levine, a physician who is chief medical officer of AstraZeneca's gastrointestinal therapeutic area, explained that in the Nexium trials, Prilosec had, by chance, worked better than it normally does. He also mentioned company-generated data that showed Nexium suppresses acid better than Prilosec.

Patients taking Nexium therefore might not need over-the-counter acid suppressors as much when they are on the drug, he said.

Wilson-Norton comments that hasn't been the case with her clinic's patients.

Still, with the massive advertising push, AstraZeneca managed to capture about 17 percent of new "proton pump inhibitor" heartburn-pill prescriptions in 2001, making it the most successful launch ever in that class of drugs, according to the company's annual report, which also noted that Prilosec has lost users to Nexium. With so many patients already taking the new drug, the company will be in good shape to retain its users when cheaper generic equivalents to Prilosec hit the market in coming months.

Ads target consumers

Schering-Plough seems to be following the Nexium marketing strategy — free trials of the drug, discounts, direct-to-consumer ads — according to pharmacist Lee Vermeulen, director of the University of Wisconsin Hospital and Clinics' Center for Drug Policy.

When top-selling drugs face patent expiration and generic rivals, companies launch blockbuster retreads to hang on to customers, Vermeulen said.

"The company tries like crazy to find something to differentiate the new agent from the parent, but the clinical advantage is simply not there."

"No self-respecting physician will be swayed by the propaganda that these companies are passing off as relevant science," he said, so companies advertise directly to consumers to whip up consumer demand.