Editorial: Drug Dependency
Another medication is suspected of having life-threatening side effects and may soon be pulled from the market. Avandia, the trade name for GlaxoSmithKline’s diabetes drug rosiglitazone, was reported in the New England Journal of Medicine to increase heart attack risk by 43 percent. The analysis was conducted by Steven Nissen and Kathy Wolski of the Cleveland Clinic and compiled the results of 42 prior studies.
In its defense, the manufacturer cited other studies that showed no increased risk. And no one has yet nailed down the mechanism by which Avandia would damage the heart, although possibilities include its tendency to boost low density lipoprotein (“bad”) cholesterol (by an average of 19 percent), precipitate congestive heart failure, and reduce blood counts. For now, Avandia remains on the market.
Avandia is the latest in a long series of drugs that have turned out to present serious potential risks. Just last December, Pfizer pulled the plug on torcetrapib, a drug that was supposed to raise high density lipoprotein (“good”) cholesterol, but was associated with unexpected deaths in human tests. Premarin, used for “hormone replacement,” increases the risk of heart disease, cancer, and stroke. The painkiller Vioxx caused thousands of deaths from heart attacks and strokes.
All these cases have left public health officials and journalists wringing their hands, wondering what we can do if drugs let us down.
The first answer, of course, is to focus on the causes of illness. No clinician believes that type 2 diabetes is caused by a rosiglitazone deficiency. Rather, it is largely the result of diet and lifestyle. Although genes play a role in susceptibility, the meaty, fatty Western diet is strongly associated with whether the disease manifests or not. Similarly, genes influence heart disease risk one way or another. A person who avoids tobacco and animal products and remains physically active has a strong measure of protection.
Some doctors are pessimistic about the benefits of diet changes, because conventional diets have been disappointing. However, going a step further—eliminating animal products, minimizing oils, and avoiding sugar and other high-glycemic-index foods—is dramatically more effective. Moreover, the “side effects” of vegetarian and vegan diets are all good ones. In addition to helping control diabetes, they also trim waistlines, cut cholesterol, and lower blood pressure.
This does not mean that there is no role for medication. But most patients treated with medications have never had the benefit of a really good diet that might have prevented their condition or made it more manageable.
So why are blockbuster drugs presenting unforeseen risks? Two reasons: First, drug companies now focus on products for long-term use. Rather than eking out profits from antibiotics used for a week or two or vaccines administered just once, they are investing in drugs designed to become a permanent part of your life. So toxicities that might not show up over the short run may well add up as the years go by.
Second, drug companies continue to rely on animal tests, which often fail to show the dangers faced by human patients. Newer test methods that can more accurately predict the results in patients will mean safer medications. And when diet changes are used to their full effect, medications may be needed much less frequently.
Neal D. Barnard, M.D.
President of PCRM