The radio alarm clock on your bedside table strikes midnight but you’ve been tossing and turning in bed for hours. Your mind has been racing to organize tomorrows chores, your work, and next weekend’s plans. 

When your mind won’t seem to shut down, you may have tried implementing a number of sleep-promoting strategies. You’ve tried meditation, journaling, sleep hygiene tips, natural sleep aids, yet still, you just can’t fall asleep. It’s at this point that you might start to consider those over-the-counter sleeping pills for relief. 

But unfortunately, while most of the over-the-counter sleep aids might help as a temporary solution to get that oh-so-critical slumber, there are a few major caveats worth considering first.

You can’t use them for more than a couple weeks because they might have a counterproductive effect — fanning the flames of insomnia, especially when you stop taking them. 

Antihistamines

The antihistamines merit special mention here. Yep, you read that correctly, these are made with the active ingredients in allergy and cold medicines. Part of the problem is that your brain can build up a tolerance to these antihistamines' sedative effects. 

After a period of time, they stop working at the printed dose and you’re back to square one in search of a remedy for your sleep issues again. 

The reason these are called antihistamines is that they block a brain chemical called histamine, which otherwise keeps you awake and alert. 

How OTC antihistamines work

The antihistamines used as an OTC sleep aid readily cross the blood-brain barrier. Inside the brain, these medicines also tame another brain chemical called acetylcholine (in addition to histamine), which stirs up many of the following health issues: 

  • Next-day hangover, sleepiness, and grogginess
  • Unrefreshing sleep that kills the major purpose of taking a sleep aid
  • Confusion and inability to concentrate or think clearly
  • Dry mouth
  • Constipation
  • Inability to pee 
  • Pounding heartbeat
  • Blurry vision
  • Falls (drowsiness, dizziness, and low blood pressure can increase the risk of falls, especially for the elderly.)
  • Memory issues as serious as Alzheimer's disease in heavy, long-term users 

Most of these side effects become more pronounced with age. A report published in the JAMA Internal Medicine showed a link between OTC sleep aids and impaired thinking and memory in the elderly. 

The sleep benefits of these OTC sleep aids come at the expense of serious side effects. Clinical experts at Harvard even suggest the risks outweigh the benefits when using antihistamines as a sleep aid. In 2017, the American Academy of Sleep Medicine recommended avoiding common over-the-counter antihistamines for tackling chronic insomnia

The OTC dilemma for the elderly 

Unfortunately, our sleep gets worse as we age due to the altering of brain chemistry and patterns as we get older. Compounding the problem, as we advance in our years we become more sensitive to OTC sleep aids. 

As you might expect, as we get older and a full restful night’s sleep becomes more difficult to attain, people start to look for solutions. Studies show that older adults in their 60s and 70s start taking these sleep aids more frequently. A clinical review shows that about 47% of people aged 75 years and up will overshoot the recommended daily use instructions of these drugs. 

Why do you develop tolerance to OTC sleep aids?

When you overuse antihistamines, your brain becomes desensitized or less sensitive to their tranquilizing effects over time. You might increase the dose in pursuit of sleep, but at the expense of greater risk to your health. 


It is possible to overdose on over-the-counter  sleep aids, which can result in what is known as antihistamine toxicity


Common Antihistamines used as OTC Sleep Aids

Most over-the-counter sleep medications contain one of two antihistamines: diphenhydramine and doxylamine. Let’s take a look at the difference between these two types of antihistamines. 

Diphenhydramine (DPH)

Apart from being a sleep aid, DPH is also used against allergic reactions as well as cough and cold symptoms. The US Food and Drug Administration (FDA) lists diphenhydramine as a safe and effective nighttime sleep aid for occasional disturbed sleep.

DPH usually takes more than 30 minutes to one hour to put you to sleep. The sedative (drowsy) effects only last for four to six hours. It’s important to note that sedation is not sleep. It may knock your brain out for some hours, but it does not look the same as natural sleep when analyzed electrophysiologically. As a consequence, the sedating nature of DPH will not be produce all the benefits that natural sleep provides.

DPH will also disrupt your sleep architecture, so the sleep you get will likely be lower quality than you expected. This is perhaps because the drug amplifies the lighter phases of your sleep to the detriment of deep, restful sleep. The lighter sleep throughout the night, in turn, translates into next-day hangover and fatigue. 

On the upside, the hangover effects don’t last for long. This is because the half-life of this antihistamine varies from 3.4 to 9.2 hours. This means that half of the drug will be cleared from your system in less than 9.2 hours after you've stopped taking it. 

Tolerance to DPH also builds up pretty quickly and according to the Mayo Clinic, the longer you use it, the less likely it will help you sleep. For this reason, it should be used only in short-term cases of sleeplessness, if at all.

Brands of Diphenhydramine

  • Benadryl
  • Vicks ZzzQuil Nighttime Sleep Aid
  • Sominex
  • Nytol
  • Tylenol PM (also contains a pain-reliever named acetaminophen)
  • Sleepinal
  • Compoz
  • Sleep Eze
  • Unisom SleepGels

Doxylamine succinate 

This OTC antihistamine sleep aid is stronger than diphenhydramine. To date, the FDA has only approved one brand of doxylamine (Unisom SleepTabs) as a temporary fix for trouble sleeping. 

The half-life of doxylamine succinate in about 10 to 12 hours. You may stay asleep a bit longer but you will also likely feel groggy and tired for longer the next day. 

Brands of Doxylamine succinate

When used as a sleep aid, doxylamine succinate is the active ingredient in: 

  • Nighttime Sleep Aid
  • Kirkland Sleep Aid
  • Unisom SleepTabs

Is there a safer alternative to OTC Sleep Aids?

Fixing your sleep problems is best achieved through a holistic approach. Cognitive-behavioral therapy for insomnia (CBT-I), which is a form of talk therapy, has been shown in studies to be more effective at turning around deeply entrenched sleep problems.

In many ways, this shows that, as much as sleep is chemical, it is also profoundly linked to our behaviors — how we manage stress, how we approach winding down our minds for sleep, how we prioritize sleep in our daily routine. 

As such, at Remrise, we believe that a great day starts with a good night’s sleep. Achieving a good night’s sleep can mean re-evaluating many sleep-related priorities. This can include re-exploring meal timing, initiating a pre-sleep routine and bedtime, and experimenting with cutting out caffeine in the afternoon as well as alcohol in the two to three hours before bed.

At Remrise, we’ve also apply a traditional Chinese medicine (TCM) approach toward health, with a particular focus on sleep. This translates into blending some personalized TCM formulas into our supplements to facilitate long-term improvement in your sleep health. 

To learn more about how TCM addresses sleep problems, read this.

Sometimes poor sleep is the result of poor sleep hygiene and can be improved with some simple lifestyle changes. Learn more

Glossary

Blood-brain barrier: A tight gap that serves as a conduit, allowing the transit of only vital molecules between the blood and brain. Medicines that breach this barrier tend to mess up with your brain functions.

Food and Drug Administration (FDA): A federal organization of the US Department of Health and Human Services that regulates the safety and effectiveness of a variety of foods, drugs, vaccines, and medical devices.

Insomnia: Inability to fall asleep and/or stay asleep.

Histamine: A chemical produced in various body tissues. It is a prime driver of allergic reactions. In the brain, it plays a pivotal role in keeping you wide and alert.

References

  1. Albert, S. M., Roth, T., Toscani, M., Vitiello, M. V., & Zee, P. (2017). Sleep Health and Appropriate Use of OTC Sleep Aids in Older Adults-Recommendations of a Gerontological Society of America Workgroup. The Gerontologist, 57(2), 163–170.
  2. Gray SL, Anderson ML, Dublin S, et al. Cumulative use of strong anticholinergics and incident dementia: a prospective cohort study. JAMA Intern Med 2015;175:401-7.
  3. Culpepper, L., Wingertzahn, M.A. Over-the-Counter agents for the treatment of occasional disturbed sleep or transient insomnia: a systematic review of efficacy and safety Prim Care Companion CNS Disord,17 (2015).
  4. Richardson GS, Roehrs TA, Rosenthal L, Koshorek G, Roth T. Tolerance to daytime sedative effects of H1 antihistamines. J Clin Psychopharmacol. 2002;22:511–5.
  5. Sateia MJ, Buysse D, Krystal AD, et al. : Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia in Adults: An American Academy of Sleep Medicine Clinical Practice Guideline. J Clin Sleep Med. 2017;13(2):307–49.
  6. Sicari V, Zabbo CP. Diphenhydramine. [Updated 2019 Apr 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526010/
  7. Drugstore sleep aids may bring more risks than benefits. Harvard Women's Health Watch, Harvard Medical School. December, 2018. Accessed at: https://www.health.harvard.edu/staying-healthy/drugstore-sleep-aids-may-bring-more-risks-than-benefits
  8. Sleep aids: Understand over-the-counter options. Mayoclinic. October 16, 2019. Accessed at: https://www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/sleep-aids/art-20047860
  9. Medications that Affect Sleep. National Sleep Foundation. Accessed at: https://www.sleepfoundation.org/articles/medications-affect-sleep
  10. National Center for Biotechnology Information. PubChem Database. Doxylamine, CID=3162, https://pubchem.ncbi.nlm.nih.gov/compound/Doxylamine (accessed on Nov. 12, 2019)