One of the most popular sectors in the OTC pharmacy biz during the last decade has been “PM” pain relievers. Drug companies take a popular brand like Advil, Aleve, Bayer, Excedrin, Motrin, Tylenol and add a sedating antihistamine such as diphenhydramine to the mix. That turns a pain reliever like acetaminophen, aspirin, ibuprofen or naproxen into a nighttime (or PM) pain reliever. Sales have been terrific, but might diphenhydramine contribute to memory loss?
A Remarkable Reversal:
Q. My wife had been having sleep problems for years, and had begun taking Tylenol PM every night (for the diphenhydramine). Over time she began experiencing memory loss, enough that it affected her work and home life. Her family has some incidence of age-related dementia or Alzheimer’s, so this was very worrisome.
After reading one of your columns this year we connected the dots, and she abandoned the sleep aid. It is about six months later, and she feels that she has nearly entirely recovered her mental acuity. She feels SO much better mentally, and her communication skills have been restored to normal levels. I’m writing to express our thanks.
A. Diphenhydramine (DPH) is a sedating antihistamine that is found in almost all over-the-counter “PM” pain relievers. It is also found in some OTC sleeping pills and allergy drugs like Benadryl.
Diphenhydramine and the Brain:
A recent review of sleep medicines for older adults concluded that “Diphenhydramine should be avoided in the elderly” (Clinical Therapeutics, online, Oct. 14, 2016). The authors note:
“Grogginess, drowsiness, confusion, and memory loss have been well described with use of diphenhydramine. Community-dwelling older adults were shown to have reduced alertness, diminished memory task performance, and impaired episodic memory with diphenhydramine.”
DPH, like many other drugs, affects brain function through the neurochemical acetylcholine. You can learn about other medications that contribute to confusion and memory loss in our Guide to Drugs and Older People.
Anyone who would like a copy, please send $3 in check or money order with a long (no. 10) stamped (68 cents), self-addressed envelope:
Graedons’ People’s Pharmacy; No. O-85,
P. O. Box 52027
Durham, NC 27717-2027.
It can also be downloaded from this website in PDF form in our Guide library.
The People’s Pharmacy Bottom Line:
We have never understood why PM pain relievers have become so very popular. Many people wake up in the morning feeling groggy from the after-effects of diphenhydramine. What’s more, DPH has strong anticholinergic activity. That is not good for the brain, especially if you are taking other drugs with anticholinergic action. If you would like to read more about this problem, here is a link to our article, “Can Popular Antihistamine (Benadryl) Cause Brain Fog?”
Share your own experience with PM pain relievers in the comment section below.