A University of Georgia study has found that three-quarters of people prescribed antidepressant drugs receive the medications for a reason not approved by the federal Food and Drug Administration.
This practice, known as off-label prescribing, is legal and intended to give physicians the flexibility to prescribe the drugs that are best suited to their patients' needs. And while study authors Dr. Hua Chen and Jack Fincham acknowledged that there are legitimate uses for off-label prescribing, they said that in many cases physicians write off-label prescriptions based on limited or anecdotal evidence.
"Most off-label drug mentions have little or no scientific support," said study co-author Jack Fincham, A.W. Jowdy Professor of Pharmacy Care at the University of Georgia College of Pharmacy. "And when I say most, it's like 70 to 75 percent. Many patients have no idea that this goes on and just assume that the physician is writing a prescription for their indication."
The study, published in the June issue of the Journal of Clinical Psychiatry, examined rates of off-label prescribing for drugs that act on the central nervous system. The researchers found that 75 percent of antidepressant recipients, 80 percent of anticonvulsant recipients and 64 percent of antipsychotic recipients received at least one of these medications off-label.
Chen, an assistant professor at the University of Houston who lead the study when she was a doctoral student at UGA, said the findings reveal a significant gap in the nation's drug safety system. The FDA approval process is widely regarded as the world's most rigorous, but off-label prescribing regularly exposes consumers to drugs that are untested for their condition.
"There's a big gap between this very strict approval process and this very liberal utilization practice," Chen said. "Something must be done to fill this gap."
The researchers examined data on drugs prescribed to 107,000 Georgia Medicaid recipients in 2001. The researchers used Medicaid data because it is comprehensive and easily accessible, and said the results are likely to be comparable in other states.
Fincham, who is also author of the book, Taking Your Medicine: A Guide to Medication Regimens and Compliance for Patients and Caregivers, said that considering the aging population and the increasing likelihood of off-label prescribing with age, the number of people receiving off-label prescriptions will likely increase in the coming years.
Chen and Fincham note that the off-label use of central nervous system drugs can account from anywhere from 25 percent to 80 percent of a drug's annual sales. In the case of the epilepsy and nerve damage drug Neurontin (gabapentin) nearly all - 98 percent - of patients received the drug off label in 2001. The drug was commonly prescribed for psychiatric conditions such bipolar disorder as well as for conditions such as migraine headaches and back pain.
Although off-label prescribing is legal, pharmaceutical companies cannot legally promote an off-label use unless studies support its use. In 2004, pharmaceutical company Pfizer paid $430 million and pleaded guilty to a lawsuit that charged its representatives illegally marketed Neurontin for unapproved uses. Last year, the FDA asked the company to review its data to assess whether Neurontin is linked to suicide attempts.
"There have been some horror stories recently," Fincham said. "And one of those was Neurontin."
The researchers said the high rate of off-label prescribing for antidepressants likely stems from the high degree of overlap in symptoms among various mental illnesses. The high rates of off-label prescribing of powerful antipsychotic and anticonvulsant drugs for the elderly underscores the lack of effective treatments for Alzheimer's disease and other forms of dementia.
Chen and Fincham said a greater emphasis on evidence - based medicine, which relies on data rather than anecdotal evidence, would ensure greater safety in off-label prescribing. They also urge physicians to tell their patients when and why they prescribe a drug off label.
"Physicians have the right to prescribe any medication off label," Chen said, "but they also have the responsibility to inform patients that this medication is being used off label."
Fincham encourages patients to be their own best advocate and to ask questions about the drugs their doctors prescribe.
"There are legitimate uses for off label prescribing," he said. "But knowing this information sets up an opportunity for you to talk to your physician or talk to your pharmacist about exactly why you're being prescribed this drug. And I encourage people to do that in all cases and with all drugs."