A Dangerous Myth: If It's Over The Counter, It Must Be Safe - Medical Myths - Harvard Commentaries

The temptation is great. The convenience can be irresistible. You don't feel well, and there are remedies for the asking just down the road at your local convenience store or pharmacy. Since you don't need a prescription, all you have to do is decide which item will best treat your particular problem. But that could take a while. Although it's easy to pick up a cold remedy or pain treatment without a prescription, finding the one that perfectly matches your combination of symptoms can be a challenge. This one is for sneezing, congestion and cough, but you have no cough; that one is for congestion, runny nose and fever, but you have no fever. It's no wonder that many people never get to the fine print about the potential dangers of over-the-counter medicines.

Although most nonprescription remedies are safe and effective, there is no such thing as risk-free medication. Even when taken as recommended, and even when the drug does exactly what it is supposed to do, an over-the-counter treatment can cause trouble. It is not rare at our weekly medical conferences for concerns to be raised about the possibility that treatments a person might be taking (often without their doctor's knowledge) could be contributing to the problems under discussion.

Some of the problems that may arise when taking over-the-counter treatments include:

Wrong treatment for the problem — If you take a cough suppressant for a bad cough, and if the cough is due to asthma, it's unlikely to work. In addition, while waiting for the cough suppressant to work, the asthma may get worse. The delay in getting the right treatment can be dangerous. A recent study found that yeast medications are commonly used erroneously for symptoms that may be due to a urinary-tract infection, a condition that may be complicated by spreading of the infection to the kidney, a serious illness called pyelonephritis.

Side effects — Over-the-counter therapies generally have a low incidence of serious side effects, but side effects do occur; for certain groups, those reactions can be quite serious. One example is diphenhydramine (brand name Benadryl, and others), a common remedy for allergies that often causes sedation. For elderly persons at risk of falling, diphenhydramine can provoke confusion, dizziness or falls. A hip fracture is high price to pay for the convenience of trying to treat allergies, but that's the sort of thing that can happen.

Drug interactions — Any drug, including nonprescription drugs, can interact with any other drug. To use the diphenhydramine example again, any other medication that causes sedation can interact with this medicine. For example, people who take Ambien or Xanax for sleep may find that the addition of diphenhydramine causes troublesome sedation, confusion or difficulty thinking, especially in the elderly.

Worsening of existing illness — Nonprescription medications may cause a pre-existing problem to worsen. Sometimes that happens when the previous problem was not even recognized. For example, if you have mild kidney failure or an ulcer, you may not even know it because both may be silent; over-the-counter ibuprofen (Advil and others) or naproxen (Aleve and others) may worsen your condition.

Nonprescription medicines are often taken incorrectly —The chances of a problem with over-the-counter treatments increases if the medicine is taken more frequently or in higher doses than recommended. And a recent poll suggests that such behavior is not rare — almost one-third of people admitted to taking more than the recommended doses of over-the-counter medications.

Duplicate medicines — Some nonprescription drugs are similar or even identical to prescription drugs, though often in a lower dose. It is easy to take too much of a medication because it is already present in something else you are taking. For example, Advil may seem like a good idea for a headache or muscle pain; but if you already take prescription strength Motrin for arthritis, you are already taking ibuprofen (the generic name for both medicines), and the added nonprescription medicine may simply increase the total dose into a risky range.

Unpredictable reactions — Just because a medicine is available without a prescription does not eliminate the rare and unpredictable allergic reaction.

With so many ways for things to go wrong, you may wonder why certain nonprescription medicines got that way. The types of medicines available to the public without a prescription and the decisions to allow that vary from country to country. For example, in many countries outside the United States, antibiotics are available without a prescription.

In the United States, the Food and Drug Administration carefully reviews requests by drug manufacturers to make a drug available over the counter and weighs risks based on data from hundreds or thousands of people who have taken the drug in research studies or after approval as a prescription medicine. But often people in studies are entirely healthy (except for the symptom or condition that lead to that medication's use), may not be taking other medications as you are, and are carefully screened and monitored in a way that most people taking nonprescription drugs are not. The truly rare side effects may be difficult (or impossible) to detect even after FDA approval, because there is no mandatory reporting system that records every potential problem. For all these reasons, it makes sense to be careful even with over-the-counter medicines.

Most nonprescription medicines are either less powerful versions of well-established prescription medicines (for example, ibuprofen or naproxen), particularly safe medicines for common problems (for example, ranitidine or acetaminophen), or have a well-known and extensive safety and effectiveness profile from being over the counter for many years (for example, guaifenesin as a cough suppressant in Robitussin).

Many people make the assumption that a medicine would never be available without a prescription unless it was safe. That's usually true, but keep in mind that each person is an individual with a unique set of prior medical problems, medication use, allergies and ways of responding to drugs.

For some of the problems with over-the-counter medicines, the solutions are straightforward: Read the fine print, take medicines as recommended on the label, and know your own allergies and medical problems. Use generic names of medicines, not just brand names; that will make it much easier to compare what you are already taking with the nonprescription medicines. Pay particular attention to warnings about conditions you might have that would make the medicine more risky. And when in doubt, talk your own health care professional about the advisability of any nonprescription medicine or treatment. Be sure to let him or her know what you are taking.

Don't hesitate to ask your health care professional for printed information, books or Web sites that provide reliable information about over-the-counter treatments. As with any prescription medicine, you want an unbiased, balanced and thorough review of risks and benefits — do not rely on advertisements for that.

Remember that the instructions on labels of nonprescription medicines usually represent conservative recommendations. Stick to the recommended doses and frequency of medication use. If you experience a possible side effect, stop the medicine; and if you aren't already getting better, contact your health care professional for evaluation.

The added convenience of over-the-counter therapy comes with added responsibility. Take that responsibility seriously when deciding whether to go to the convenience store for a remedy rather than seeing your doctor. Avoid “wishful thinking” — that your symptoms will always be easily treated with a nonprescription drug of your choosing. It is a myth to assume that nonprescription drugs are always a good choice or always safe. If your symptoms are unusual or severe, get some advice from your physician. But if the symptoms are something you've had before and were readily relieved with an over-the-counter treatment that you tolerated well, take advantage of the unprecedented number and variety of nonprescription options. Just don't forget to read the label one more time.

Robert H. Shmerling, M.D., is associate physician at Beth Israel Deaconess Medical Center and associate professor at Harvard Medical School. He has been a practicing rheumatologist for over 20 years at Beth Israel Deaconess Medical Center. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program.