Confusion Caused by Nonprescription Drugs

By Marcus M. Reidenberg, MD, FACP
Weill Cornell CERT
Summary by Kathleen Mazor, EdD
HMO Research Network CERT

Many nonprescription medications contain drugs that have a pharmacologic effect that can cause confusion, and disorientation. This is called delirium. The medications include most of the sleep aids, cold medicines and medicines for allergies. Elderly people are more sensitive to this adverse effect than younger people. There is no warning about this on any of these drug labels. So people might not relate this effect to the medicine and make the delirium worse by continuing the medicine. Below are summary points as well as a link to a Citizen’s Petition to the FDA requesting that an appropriate warning be added to the label. The petition outlines the scientific evidence supporting such a label.

Summary Points

What is the issue?

Certain over-the-counter medications can cause serious confusion and other problems thinking, especially in elderly people.

What medications are involved?

Most over-the-counter sleep aids, cold medicines, and allergy medicines.

What is the problem?

These medicines can cause confusion, disorientation and other problems thinking.

People taking these medicines who experience problems thinking may not realize that the problems are caused by the medicines. They may continue to take the medicine, which may make the problem worse.

Who is at risk?

Elderly people are most likely to experience confusion or problems thinking after taking these medications. Young people are also at risk if they are taking many medications since other medications can interact with these sleep aids or cold and allergy medications.

How can I tell whether my medicine causes problems for me?

Surprisingly, labels for these medicines do NOT contain a warning about this problem. The petition to the FDA is requesting this warning be added.

If you take one of these medications, notice whether you feel confused, or have other problems thinking.

Ask those around you (family members or friends) to speak up if they notice that you seem confused or show other problems thinking.

What should I do if I think my medicines are making me confused.

Stop the nonprescription drug and talk to your doctor.

Citizen’s Petition to the FDA

Posted 10/9/2013

This note can be found online at

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