“On March 23, 2009, a federal court issued an order directing the FDA, within 30 days, to permit the Plan B drug sponsor to make Plan B available to women 17 and older without a prescription. The government will not appeal this decision. In accordance with the court’s order, and consistent with the scientific findings made in 2005 by the Center for Drug Evaluation and Research, FDA notified the manufacturer of Plan B informing the company that it may, upon submission and approval of an appropriate application, market Plan B without a prescription to women 17 years of age and older.”

The product won’t become available to women of that age until the manufacturer of Plan B submits and receives approval for a labeling change

"It would be wonderful if one could take a drug and be smarter, faster or have more energy," said Dr. Nora Volkow, director of the National Institute on Drug Abuse, who led the study with a Brookhaven National Laboratory scientist. "But that is like fairy tales. We currently have nothing that has those benefits without side effects."

The study, appearing in Wednesday's Journal of the American Medical Association, may bust the myth that the drug is safe for healthy people, experts said.

Provigil is approved to treat excessive daytime sleepiness caused by narcolepsy. On the market since 1999, it's the flagship product of Cephalon Inc. of Frazer, Pa., and its sales approached $1 billion last year. The company is developing a spin-off called Nuvigil.

Modafinil's reputation as a brain enhancer stems from an Air Force study that found it improved the performance of sleep-deprived fighter pilots. College students buy and sell it illegally, as they do Ritalin and Adderall, to stay alert while studying.

Several scientists recently wrote in the journal Nature that healthy people should have the right to boost their brains with pills like Provigil. One author of that commentary, brain scientist Martha Farah of the University of Pennsylvania, said the new study "goes to show that we need a little caution and a little humility when we're messing around with our brain chemistry."

"But even now, after all the years that it has been on the market, we are still learning things about it that are relevant to its safety," Farah said.

The men in the study were 23 to 46 years old. They received either a dummy pill or modafinil. Effects were measured by PET scans, which showed that the drug increased dopamine, the brain's "feel-good" neurotransmitters.

Modafinil once was thought to be safer than conventional stimulants because it was believed that it did not engage the brain's dopamine system, which is linked with addiction. Studies in mice and monkeys suggested otherwise.

The new study is the first human evidence that a typical dose of modafinil affects dopamine in the brain as much as a dose of Ritalin, a controlled substance with clear potential for dependence.

Volkow said modafinil acts slowly when swallowed and is difficult to inject, making it less likely to be abused. Its high price, about $10 per pill compared to Ritalin at $2 per pill, also makes it less attractive to people seeking a high. That may change when generics become available in 2012, Volkow said.

Jeffry Vaught, chief science officer for Cephalon, said the company has seen no evidence the drug is highly abused.

"If abuse is a problem with modafinil, it's minimal at best," Vaught said. "We're not seeing it used at rave scenes."

Prescribing information for the drug warns of severe rashes and other side effects such as headache, nausea and anxiety. Cephalon doesn't support the drug's use as a cognitive enhancer.

"There's no substitute for sleep," Vaught said.

In a closely watched case, the court ruled 6-3 that patients can file lawsuits against drug companies in state courts for inadequate or flawed safety warnings, even though the Food and Drug Administration is responsible for reviewing and approving drug labels.

The case involved a Vermont musician who lost her right forearm after she suffered complications from a drug made by Wyeth. A jury awarded her $6.7 million.

Wyeth unsuccessfully argued she had no right to sue because the FDA had approved the label.

It’s unclear whether the ruling will hurt the Boston area’s biotechnology industry, which is considered key to the state’s economic growth.

David Ferrera, a partner with the Boston law firm Nutter McClennen & Fish, said the ruling would almost certainly spur drug companies to include lengthier safety warnings on their drug labels – citing even the rarest of potential side effects – to shield themselves from liability.

The FDA would still have to approve such changes.

If that happens, industry advocates warn, it could further complicate drug labels, making them harder for doctors to understand and potentially scaring off patients who could benefit from such therapies.

But some consumer advocates have long complained that drug companies and the FDA haven’t done enough to warn patients about potential side effects.

Overall, Ferrera predicted, the ruling probably would have little impact because the justices simply upheld a lower court’s judgment.

In addition, Ferrera said, such suits had already been permitted in many states for decades, even though the drug industry has hoped the court would put an end to such litigation.

Diane Bieri, chief counsel for Pharmaceutical Research and Manufacturers of America, the industry’s main trade group, said companies might decide to update their drug labels more frequently to limit exposure to lawsuits. But Bieri said she wasn’t sure whether drug makers would make any other changes, such as issuing more safety warnings.

“I think it’s too soon to tell how companies will respond to the ruling,” Bieri said. “Like PhRMA, they are still reviewing the ruling.”

For now, Bieri said, the ruling is likely to introduce some uncertainty as companies try to figure out exactly what it means.

Boston-area companies had a muted reaction.

Genzyme Corp. and Biogen Idec Inc., the state’s largest biotechs, and both based in Cambridge, declined to comment. EMD Serono Inc. in Rockland, another major player, did not return a call seeking comment.

And two key trade groups, the Massachusetts Biotechnology Council and the national Biotechnology Industry Organization, declined to comment.

Chronic use of metoclopramide has been linked to tardive dyskinesia, which may include involuntary and repetitive movements of the body, even after the drugs are no longer taken. These symptoms are rarely reversible and there is no known treatment.

Metoclopramide is available in a variety of formulations including tablets, syrups and injections.

Names of metoclopramide-containing products include Reglan Tablets, Reglan Oral Disintegrating Tablets, Metoclopramide Oral Solution, and Reglan Injection.

Manufacturers will be required to implement a risk evaluation and mitigation strategy [REMS] to ensure patients are provided with a medication guide that discusses this risk. Current product labeling warns of the risk of tardive dyskinesia with chronic metoclopramide treatment.

Although the FDA is not required to follow the advice of their advisory panel, they usually follow their panel’s recommendation.

According to an FDA analysis, more than 3,000 serious reports of Darvon and Darvocet problems were identified, with most involving suicides, addiction and overdoses.

The advisory panel voted 14 to 12 to recommend a recall.