People with insomnia are caught between two hard rocks. On the one hand, they are told that lack of sleep can lead to all sorts of health problems including high blood pressure, forgetfulness, diabetes and weight gain. It’s not surprising that they turn to over-the-counter “PM” sleep aids. But once you start taking drugs containing the antihistamine diphenhydramine (DPH), how can you phase off PM sleeping pills?
It’s Hard to Find Instructions About Stopping PM Sleeping Pills!
Q. I have taken diphenhydramine at bedtime for many years. Is there a way to stop this medication? When I don’t take it, I have problems falling asleep.
A. Diphenhydramine (DPH) is the antihistamine in Benadryl. It causes drowsiness. DPH is now found in most nighttime (“PM”) pain relievers such as Advil PM, Aleve PM and Tylenol PM. If you see “PM” in the name, chances are pretty good that DPH is the ingredient that causes drowsiness in the product.
Drug companies suggest that their pills are for “occasional” sleeplessness rather than nightly.
Some products also state:
“Stop use and ask a doctor if
■ sleeplessness persists continuously for more than 2 weeks. Insomnia may be a symptom of a serious underlying medical illness.”
Are PM Sleeping Pills Habit Forming?
Manufacturers of PM sleeping pills make it quite clear that DPH is a non-habit-forming sleep aid. They may state that their pills do not cause physical dependence. That should mean there is no rebound insomnia when someone stops.
A drug company might well explain that if someone who has chronic sleeping difficulties takes diphenhydramine to fall asleep, the problem might return when the drug is stopped. That is a legitimate point. But we have not been able to find large-scale, well-controlled trials that test this hypothesis.
How Would We Know If PM Sleeping Pills Are NOT Habit Forming?
Here is the kind of study we would love to see (Gastroenterology, July, 2009). It was designed to test heartburn medicines called PPIs (proton pump inhibitors). Healthy volunteers (who did not have heartburn or reflux symptoms) were given esomeprazole (Nexium) for 8 weeks followed by placebo for 4 weeks. Another group got placebo for 12 weeks. No one was told what they were getting.
Remember, these were all healthy volunteers! No heartburn. The participants who got the PPIs for 8 weeks experienced “acid-related symptoms” after withdrawal of esomeprazole. So…rebound hyperacidity with symptoms is a thing.
We would love to see such a trial for DPH. In other words, a large group of healthy volunteers without insomnia would be given PM sleeping pills for 8 weeks. Then unknown to them, they would be switched to placebo for the last 4 weeks. Their sleeping behavior would be compared to another group that was on pure placebo for 12 weeks. Would there be any rebound insomnia in the DPH group? So far, we have not seen such a study, nor is one likely to show up any time soon.
Should People Take DPH for Weeks, Months or Years?
Sleep experts we have consulted do not recommend regular use of this antihistamine for insomnia. DPH has strong anticholinergic activity. That means it interferes with the action of the brain neurotransmitter acetylcholine. Anticholinergic drug use has been associated with mild cognitive impairment (Alzheimer Disease and Associated Disorders, Jan-March, 2023). But are there hidden dangers?
This woman has taken DPH for years:
Q. I have had a great deal of trouble sleeping since my husband passed away. For many years I have taken Tylenol PM or Advil PM along with alprazolam.
I have read that alprazolam can contribute to dementia, so I am trying to get off it. What about PM sleeping pills? Could they also contribute to dementia?
A. Alprazolam (Xanax) is approved for treating anxiety and panic, not insomnia. This drug is a benzodiazepine, in the same class as diazepam (Valium) and lorazepam (Ativan).
There is an association between dementia and the use of drugs like alprazolam (JMIR Medical Informatics, Aug. 4, 2020; Expert Opinion on Drug Safety, May, 2015). Regular use of anticholinergic drugs like diphenhydramine (the PM in nighttime pain relievers) might also contribute to cognitive impairment (American Journal of Geriatric Psychiatry, March-April, 2003). You can find a list of drugs with anticholinergic activity at this link:
Where Can I Find A List of Anticholinergic Drugs?
People taking anticholinergic drugs over a long period of time may be at greater risk of developing dementia.
Cognitive behavioral therapy for insomnia (CBT-I) is a safe alternative.
Do NOT Stop Alprazolam Suddenly!
Stopping alprazolam suddenly could lead to worse insomnia or other withdrawal symptoms.
Symptoms of Benzodiazepine Withdrawal:
- Anxiety, agitation, jitteriness, disorientation
- Dizziness, brain zaps, shock-like sensations
- Insomnia, irritability, impaired concentration, faulty memory
- Fear, panic, depression, suicidal thoughts
- Digestive upset, diarrhea
- Tremor, headache
- Tinnitus or ringing in the ears
A story from a reader:
“I take alprazolam once per day at maximum, but I ran out a week ago because of no time to pick it up. As a result, I have insomnia, the ‘brain zaps,’ agitation. For three days, I’ve been walking around having perpetual heart attack symptoms; no fun at all.”
PM Sleeping Pills and Dementia:
The PM part of your nighttime pain reliever is diphenhydramine (DPH). This antihistamine has strong anticholinergic activity. Drugs in this class have also been linked to an increased risk for dementia (JAMA Internal Medicine, March, 2015).
Learn more about anticholinergic drugs and memory at this link.
There is considerable controversy about relying on DPH as a sleep aid or in PM sleeping pills. One analysis published in The Primary Care Companion for CNS Disorders (online, Dec. 31, 2015) reviewed randomized controlled studies conducted over the previous 12 years.
The authors concluded:
“Together, the scientific evidence suggests limited beneficial effects of diphenhydramine on sleep, an increased risk of next-day performance impairments, and potential rebound insomnia following discontinuation, although additional studies are needed to confirm these safety risks.”
Another study published in the American Journal of Geriatric Psychiatry (Mar-Apr, 2003) concluded:
“A group of 1,627 individuals age 65 and over were recruited and assessed during 1987-1989 and re-assessed during approximately biennial waves. Data included sleep medications, demographics, depressive symptoms, sleep complaints, and cognitive functioning (Mini-Mental State Exam [MMSE]).
“As the cohort aged, prescription sedative-hypnotic use remained relatively stable, whereas over-the-counter sedative use, principally diphenhydramine, increased substantially. The association of this drug with cognitive impairment in persons without dementia highlights its potential for causing adverse reactions in older adults.”
As we have mentioned many times on this website, it is the additive effect of various anticholinergic drugs that concerns us most. Someone who is taking PM sleeping pills together with a drug for overactive bladder and an antihistamine for allergies along with a sedative like alprazolam could have a substantial anticholinergic “burden.” Additive drug interactions of this nature are worrisome.
Did Sleeping Pill Cocktail Leave Insomniac Zombified?
When chronic insomniacs have a hard time getting a good night’s sleep their doctors sometimes come up with some worrisome sleeping pill cocktails.
Final Words About DPH As a Sleeping Pill:
We have been subscribing to The Medical Letter on Drugs and Therapeutics for decades. It is an excellent objective resource.
Here is what it states about first-generation antihistamines such as diphenhydramine:
“These drugs are sedating, but there is little acceptable evidence that they improve the quality or duration of sleep, and tolerance to their sedative effects may develop rapidly. First-generation antihistamines can impair next-day performance, including driving. They can cause anticholinergic adverse effects, such as dry mouth and urinary retention, which can be troublesome in elderly patients. Chronic use of anticholinergic drugs has been associated with an increased risk of dementia.”
We provide more details about cognitive behavioral therapy (CBT) and many nondrug alternatives in our eGuide to Getting a Good Night’s Sleep. This online resource is available in the Health eGuides section of this website.
Please share your own experience with DPH or alprazolam in the comment section below.