The Food and Drug Administration recently approved a drug to treat attention deficit hyperactivity disorder (ADHD) that its manufacturer said is harder to abuse than traditional stimulants.

The amphetamine-based drug called Vyvanse is a prodrug -- a drug whose ingredients are only activated when they interact with enzymes in the stomach -- making it more difficult to abuse, said Matt Cabrey, spokesman for the drug's manufacturer, Shire PLC.

Several clinical studies tested the drug's "abusability" by giving it to people with a history of substance abuse. Subjects were unable to achieve a state of euphoria -- or "high" -- by snorting, injecting, over-dosing orally or other methods, Cabrey said.

Cabrey said Vyvanse is the first prodrug stimulant approved for treatment of ADHD.

Although Vyvanse's manufacturer is looking to market the drug as harder to abuse, the Drug Enforcement Administration is considering making it a Schedule II drug. Drugs in this classification have a high potential for abuse. Other Schedule II drugs include cocaine and methamphetamine. This category is the most highly regulated of prescription drugs, Nicholson said.

The DEA has not yet reached a decision about how to categorize the drug, which might make the list because it is amphetamine-based.

If used improperly, traditional ADHD drugs can be habit-forming and potentially life threatening, said Victoria Stout, psychiatrist at Counseling and Psychological Services (CAPS). Potential effects of misuse include increased heart rate, weight loss, insomnia, agitation, hallucinations, seizures and the exacerbation or onset of psychotic disorders such as schizophrenia, Stout said.

Though Stout said she has not heard of much serious stimulant abuse -- such as snorting or injecting -- at Penn State, she is aware that many students share or misuse the drugs. Most misuse occurs when students have a heavy workload, such as during finals week, she said.

If taken as directed, ADHD drugs are difficult to abuse because the medication is gradually released into the bloodstream throughout the day and does not provide a "high," said Cynthia Huang-Pollock, assistant professor of psychology.

It is difficult to determine the total number of Penn State students with ADHD because students are treated by a variety of sources both on and off campus. According to Huang-Pollock, incidence of ADHD in elementary school-aged children is 3 to 5 percent, and about 50 percent of those children continue to have ADHD into adulthood.

Vyvanse will carry a "black-box" warning -- the government's strongest for prescription medication. Dr. Jeanette Ramer, a developmental pediatrician at the Penn State Children's Hospital, said black-box warnings are labels that warn users of potential side effects that may have appeared in pre- or post- marketing data. Vyvanse did not provide details for the reasons for the black-box warning.

Ramer said she worries that the black-box warning may be an indirect maneuver to protect drug companies from lawsuits. The label places more responsibility on doctors and patients and takes some of the burden off drug companies, she said. By informing patients of the potential risks of the drug, the company is reducing the amount of responsibility they would have should these effects take place.

The FDA-approved Vyvanse Feb. 23, the same week that it asked all ADHD drug manufacturers to warn patients of the potential for mental and heart problems associated with the medicines.

Stimulant medications can have a negative impact on the heart and cardiovascular health, Huang-Pollock said. Extreme cases are rare, however, and are often the result of a pre-existing condition or the interaction of multiple medications, Ramer said.

Shire is also the manufacturer of the top-selling Adderall XR and hopes to phase patients from the older drug to Vyvanse in 2009. The move is an effort to stave off the competition that Adderall XR will face from cheaper generic versions.

Stout did not know whether University Health Services would carry Vyvanse. She said she would not automatically switch her patients to the new drug.

Ramer said she would be hesitant to start prescribing Vyvanse over Adderall XR, because she believes Adderall to be highly effective.

"They'd have to do a lot convincing," she said.