One of the last big secrets of American medicine involves a practice called "off-label" prescribing. Most people assume that the pills their doctors prescribe have been carefully tested and approved for their condition. They don't realize that one out of five prescriptions written in the U.S. is for a purpose that the Food and Drug Administration has not vetted.
The FDA allows a drug company to seek approval for one specific condition. All the company need do is demonstrate that the medicine works better than placebo for that particular problem.
Once that hurdle is overcome, a quirk in the system lets the drug loose. It can be prescribed for anything a doctor deems appropriate, whether there is evidence to support its use or not. The FDA does not regulate the practice of medicine.
One fascinating example of off-label use involves the notorious drug thalidomide (Thalomid). It caused horrible birth defects during the 1960s when it was prescribed in Europe as a sedative. During the 1990s, the FDA approved Thalomid for the treatment of a rare form of leprosy.
The company showed that the drug worked for this very narrow indication. The manufacturer knew it couldn't get rich on fewer than 100 patients who might need the treatment each year, but it hoped that the drug would prove useful for more common conditions.
This gamble paid off. Before long, physicians started prescribing Thalomid for multiple myeloma (a blood cancer) and many other types of cancer, along with other hard-to-treat conditions such as Crohn's (inflammatory bowel disease), HIV, macular degeneration and rheumatoid arthritis.
Within a few years, the maker of Thalomid was bringing in millions of dollars, mostly from cancer treatment, not leprosy. Eventually, Thalomid was approved for treating multiple myeloma, but it is still being used off-label for many other conditions.
A new study (Archives of Internal Medicine, May 8, 2006) has found that more than 150 million prescriptions are being written for unapproved indications. Antidepressants (Prozac or Paxil, for instance) are prescribed for premature ejaculation. We'll probably never know whether the benefits outweigh the risks for this purpose, since the company is not required to do any additional research.
Other examples of such off-label prescribing include beta-blocker heart medicines (propranolol, metoprolol, atenolol) for stage fright or performance anxiety. Neurontin (gabapentin) is an epilepsy medicine that has also been approved for pain that lingers after a shingles attack. But it is probably used more frequently for chronic pain, bipolar disorder, migraines, attention-deficit disorder or drug and alcohol withdrawal, as well as restless leg syndrome.
If doctors had really good data to support unapproved uses, there would be little concern. But the study found that three-quarters of the prescriptions for off-label uses are not backed up by solid evidence. That means patients are frequently participating in an uncontrolled experiment that they haven't agreed to. This could result in serious adverse reactions or even death.
The next time you receive a prescription, ask your doctor if the medicine has been approved for that use. If not, you might want to find out more about the benefits and risks before popping that pill.