OTC drugs that are quite different might share the same name

by Michael R. Cohen, R.Ph.

Published May 22, 2013, 6:05 a.m. ET

You may find it hard to believe, but FDA has no say in how many over-the-counter drugs are named. That's a great help to companies who want to market their drugs but it's a problem for those of us concerned about drug safety.

OTC users sometimes fall victim to a potentially dangerous situation that exists with many "over-the-counter drugs" (ones sold on grocery store or pharmacy shelves without a prescription). It's a problem that the public is largely unaware of, and it has led to confusion and medication errors made by consumers.

Here's the issue. I'm sure that you've noticed that companies often use the same trusted brand name for an entire line of products, even if the ingredients in each product are completely different. That happens with soap suds and deodorants but with OTC drugs people sometimes use the wrong medicine – to their detriment. So watch out if you're searching store shelves for Benadryl, Claritin or Zyrtec Eye Drops, Triaminic, Sudafed, Betadine, Surfak, Kaopectate, or AZO. What is in these products may not be what you expect.

Certain classes of OTC medications are exempt from FDA review, including thousands already on the market in 1972 prior to the Federal requirement that all drugs be approved. Companies that make medications "generally recognized as safe and effective" by FDA—and acetaminophen is among them—do not have to submit a new drug application before marketing them over-the-counter.

So some products available in your drug or grocery store do not have their product names approved by FDA. Drug companies can capitalize on a well-known, trusted, brand name, and use it for any variation or formulation of that product. It's known as "brand name extension." Unless the FDA learns of errors that might cause harm to patients, there's not much the agency can do about it.

Every now and then we hear from consumers who've come to realize that with many OTC drugs not everything is as it seems. A good example is the man whose gastroenterologist ordered the strong laxative Dulcolax to help clear his bowels before a colonoscopy. The patient bought a bottle of Dulcolax and took it just as his doctor ordered. Unfortunately though, he purchased a bottle of Dulcolax that contained the stool softener docusate, not the strong laxative bisacodyl that his doctor wanted him to take. Both products go by the name Dulcolax. The colonoscopy could not be completed.

A new situation that's about to unfurl with two new "Allegra" products. These should soon be hitting store shelves soon. However, they do not contain the same active ingredient in the original Allergra product used to treat allergies. These two new products, Allegra Anti-Itch Cooling Relief and Allegra Anti-Itch Intensive Relief, contain diphenhydramine and allantoin and are applied to the skin. You may know diphenhydramine by another name - the allergy medicine Benadryl. The only thing these new products share with the original Allegra product is the brand name and the "look" of the medicine packages. The original Allegra product contains a drug called fexofenadine, a non-sedating antihistamine.

The company that makes these "Allergra" products, Chattem (part of the Sanofi company), has used similar design elements from the Allegra package (e.g., purple-colored cartons, stylized Allegra name) to market the new products. The similarities reinforce the association of these products with the original Allegra product (Figure 1) and increase the risk of confusion.

The fact that Allegra Anti-Itch Cooling Relief and Allegra Anti-Itch Intensive Relief contain diphenhydramine and allantoin can easily be missed. The contents are not prominently displayed on the front of the package. Why is that important to know about? Someone taking another allergy or sleep medicine that also contains diphenhydramine can develop hallucinations, high body temperature, a fast heart rate, and convulsions, requiring medical treatment or hospitalization. Also, people who are allergic to or should not take diphenhydramine may not realize they should not use these new products. Many dermatologists do not like to apply diphenhydramine products to the skin because it is sensitizing and could lead to contact dermatitis.

Here is what you can do: When buying any over-the-counter (OTC) medicine, don't rely only on familiar brand names to ensure you have the right product. Read the package label carefully. In particular, read the Drug Facts label on the side or back of the package or bottle. At the top of this label you will find a list of the active ingredients. Newer products with familiar brand names may not contain the same active ingredient as the original brand product. Be sure the product you are purchasing includes the active ingredient you want to treat your current condition. If you are unsure, ask your pharmacist for help.