Have you ever wondered about the side effects of your medicine? Doctors, pharmacists, nurses and patients all have to rely on the official prescribing information approved by the FDA.
The data come from drug company clinical trials, and everyone assumes they are accurate. But how reliable is this information?
A new study raises questions about how common certain side effects may be (Drug Safety, Aug. 1, 2012). Researchers used an automated telephone system to ask patients with recent prescriptions about their symptoms.
What they found was somewhat surprising. People taking the sleep aid zolpidem (Ambien) were nine times more likely to report fatigue than would be expected based on the rates in the prescribing information.
Those taking the stop-smoking drug varenicline (Chantix) reported fatigue and muscle aches six times more often than a physician would anticipate based on drug company data. Even more striking, 3.4 percent of those contacted reported depression, compared to the “official” estimate of 0.1 percent. That suggests depression is about 30 times more common than a doctor might imagine.
A physician or pharmacist is not likely to warn a patient about a side effect that is thought to affect only one person out of 1000. If someone is not alerted to this possibility, however, he may be blindsided.
One visitor to our website reported:
“When I decided to take Chantix several years ago to stop smoking, very few side effects were mentioned. I was told I might have vivid dreams, gas or nausea.
“Not only did I have horrible leg pains, hands cramping, dreadful dreams and depression, I actually had major thoughts of killing myself. I started planning how to do it. None of these symptoms were mentioned as side effects.”
If patients are not forewarned, they may suffer side effects for a long time without realizing they could be connected to their medicine. Another example is heartburn associated with zolpidem (Ambien). Although the prescribing information mentions “dyspepsia,” a medical term for heartburn, it is rarely listed in drug databases.
Many visitors to PeoplesPharmacy.com have reported serious trouble with heartburn. One wrote:
“Within a few hours of taking zolpidem I was getting heartburn and stomach cramping. The next morning the heartburn was so bad that it felt like acid had been poured down my throat.”
Another confessed:
“I have been taking zolpidem and have had horrific heartburn for the past three months. My doctor prescribed Nexium for my indigestion. I experimented three nights ago and just took myself off the zolpidem. Since then I haven’t had any heartburn at all, nor have I needed to take Nexium.”
Many serious side effects are discovered only after a medicine has been on the market for many years. That was the case with diabetes triggered by statin-type cholesterol-lowering medicines. Suicidal thoughts associated with antidepressants are another example.
Health care providers need to realize that the official prescribing information for many medications may be incomplete or inaccurate. We look forward to a day when the FDA takes patients’ experiences more seriously as the agency revises information about adverse drug reactions.
Until that day arrives, however, you will need to be extra vigilant. In our book, Top Screwups Doctors Make and How to Avoid Them, we have several chapters on how to protect yourself from dangerous drug side effects. There is a checklist that you need to follow every time you get a a new prescription. You will also find a detailed description (along with side effects) of the most dangerous drugs in the drugstore. You will be surprised to learn how many are frequently prescribed. Hint: They include NSAIDs (nonsteroidal anti-inflammatory drugs), acetaminophen (Tylenol), corticosteroids (like prednisone) and quinolone antibiotics (Cipro, Levaquin, etc).
To learn more about adverse drug effects and interactions, check out Top Screwups!
