Before drugs come on the market, the companies that make them have to report the results of clinical trials to the federal Food & Drug Administration (FDA). Clinical trials are controlled tests of the drugs in real patients. The reports that manufacturers submit include information about side effects that patients experienced during the tests. You might think that this arrangement would mean that the FDA knows what the side effects of drugs are, so that patients can be informed about them when drugs are prescribed.

However, real life doesn’t work exactly the way you’d expect. First, clinical trials may last just a few months, even if some people are likely to take the drug for years once it is on the market. For this reason, the trials may not reveal side effects that surface over time. Second, rare side effects may be missed because the clinical trial may not include enough people to make it likely that such problems would surface. Third -- and this is the kicker -- the side effects reported are based on doctors’ beliefs about what their patients experienced, not on patients’ reports of their experience.

Dr. Ethan Basch wrote an article in the New England Journal of Medicine about this fact. He described a study involving patients being treated for cancer. Doctors reported far fewer instances of side effects than patients did. For example, doctors said that 2 or 3 patients out of 100 had loss of appetite after five months of treatment. However, about 25 patients out of 100 said that they had this symptom. Doctors reported that fewer than 10 patients out of 100 had nausea. Based on what the patients said, it was closer to 30 patients out of 100.

For all of these reasons, the information that the FDA gets may understate side effects.

Once a drug is on the market, the FDA wants to know each and every time any patient experiences serious side effects. This information helps them to understand if a drug is more dangerous than they thought it was.

Researchers have found that doctors typically dismiss patients’ reports of side effects. This situation arises even when medical research shows that the symptom the patient has is a common side effect of the drug involved. What do you think the chances are that doctors routinely report to the FDA serious side effects that patients complain about -- given that they often tell patients that there is no connection between their symptoms and the drug?

The answer is obvious: the odds that a doctor will report such side effects are low. The fact that side effects aren’t reported makes it even more likely that doctors will tell patients in the future that the symptoms they’re reporting have nothing to do with the drug they’re taking.

If the FDA doesn’t get a complete picture of side effects either in clinical trials or when the drug is on the market, how do they know if a drug is causing more serious problems than they thought it did when they approved it? How do they know when to insist that more warnings be put on the label? How do they know that a drug might need to be pulled off the market?

These answers take longer to arrive at than you might consider ideal.

What can you do about it? If you end up with a serious side effect of a drug, you can report it yourself. Doing so can help other people in the future.

Two channels exist for reporting problems with a drug. The first is to call the manufacturer of the drug directly. If your prescription drug comes in the manufacturer’s package, you may find that the phone number is printed either on the carton or on a leaflet that comes stuffed inside the carton. However, in many cases, you may not be given the manufacturer’s hotline when you buy the drug. Ironically, it is easier to find this information for over-the-counter drugs, because a phone number is usually printed on the package.

The second approach is to contact the FDA directly. The FDA runs a program called MedWatch which is set up to capture reports of side effects (also known as adverse events or reactions). Information about this program can be found at Clicking on “Reporting by Consumers” takes you to a page that offers three avenues: online, mail, and telephone. If you decide to call, the main phone number to use is (800) 332-1088. The page that explains these avenues offers a brochure titled, “Your Guide to Reporting Problems to FDA.” You can also find this brochure by Googling its title.

The brochure offers these key instructions:

  1. Report promptly. Provide contact information for the patient, for the person reporting, for the doctor or hospital if emergency treatment was needed, for the store where the drug was purchased, and for the company which made the product if this information is shown on the product’s label. Note the date on which the product was purchased. Include product codes or identifying marks from the product’s container.
  2. Keep the product and its container and labeling. They provide detailed codes that allow the FDA to tell exactly which factory made the product and what batch the drug came from.
  3. Report to the manufacturer and to the store where you purchased the product, if possible, in addition to reporting to the FDA.
  4. If you aren’t clear about how to report, go to Click on "Consumer Complaint Coordinators" to find the phone number for the local FDA Consumer Complaint Coordinator. For Arizona and southern California, the number is (949) 608-3530. Be aware that this is not a toll-free call.

By making the effort to report serious side effects yourself, you can help make it more likely that other people in the future will learn about both the benefits and the risks of a drug before they take it.