Prescription drugs used to treat attention deficit hyperactivity disorder (ADHD), such as Ritalin, Strattera, Adderall and Concerta, have been coming under fire lately.
Back in February, the Food and Drug Administration's (FDA) Drug Safety and Risk Management Board recommended that a black box warning, the strongest warning for any prescription drug, was necessary to alert patients of the potential risk for heart problems.
The basis of the warning comes from an epidemiological study by the FDA. Approximately 676,000 patients who had taken ADHD drugs at some point were part of this study. The results showed a higher-than-expected number of cases of strokes and heart attacks, especially in adults still on the medications.
The key word in all of this is epidemiological. An epidemiological study monitors a large population rather than a small, controlled group. While all of those 676,000 patients were on an ADHD drug at some point in their lives, the study does not account for other factors that could have put the patients at risk for heart problems. It also does not consider whether any of those patients were necessarily taking an ADHD drug when their heart attacks or strokes occurred.
This is probably the basis for a federal health advisory board's decision last week that Ritalin and other ADHD drugs should not carry a black box warning. While they did say that clearer labels were needed, the black box warning could do more harm than good.
The last time a black box warning got so much attention in the news was when Vioxx and Bextra, drugs used to treat arthritis, were taken off the market in the fall of 2004.
Celebrex - which, like the others, is used to treat arthritis and other kinds of pain and inflammation - is in the same class of drugs as Vioxx and Bextra, so many questioned why Celebrex remained on the market. Many were calling for a black box warning on Celebrex to warn about the increased risk of heart problems.
While Celebrex never received a black box warning, the damage had been done. Celebrex is still on the market, but it is not being dispensed nearly as much as it was prior to its black box controversy.
This is not because doctors are trying to keep their patients away from Celebrex. However, many patients hear these scary news stories and automatically assume that they should stay off a drug, even though they may not personally be at risk for the problems that get in the news. This is exactly why the federal health advisory board did not want a black box warning placed on ADHD drugs. It may prevent the people who really need them from being willing to take them.
There are risks of negative side effects, just like there are with almost any prescription-strength drug, and if a person has other factors that put them at risk for heart problems, then there is an immediate concern for whether to stay on an ADHD drug.
The important thing to keep in mind with any study that touts major risks to your health is whether it is epidemiological or clinical. In the case of Vioxx, the study was clinical, so there was an appropriate basis of concern.
For ADHD drugs, the epidemiological study does not account for several other factors involved. This is something that should be kept in mind for any prescription drug, not just the controversial ones.
Information from - Houston Chronicle, WedMD
