Before you reach into your medicine drawer tonight, read this. Insomnia is the most common sleep complaint among Americans and affects about 25 percent of the U.S. adult population who report either trouble falling asleep or difficulty staying asleep.  It is estimated that 50-70 million Americans have chronic insomnia, a sleep disruption occurring at least three times a week and lasting for more than a month.  Women report more problems falling asleep, tend to be more sleep deprived and are at greater risk for insomnia than men. 
As we age, the problem gets worse. Older Americans, those age 65 or older, make up 13 percent of our population, with a third of them taking prescription medications and 30 percent of those taking over-the-counter (OTC) medication.  A recent conference on the use of OTC sleep aids in the elderly, hosted by the Gerontological Society of America, provided me with some numbers and a disturbing sense of unease.
Fully 44 percent of Americans ages 55-84 experience disrupted sleep at least three nights out of the week.  The link between age and sleep problems is strong and appears to be due to declining health, stress, age-related changes in circadian rhythms, and living in a nursing home or health care facility. 
Insomnia has been linked to a wide range of harmful health effects, including increased blood pressure, diabetes, obesity, depression, heart attack, stroke and pain. [7,8] In an effort to get a good night's sleep, Americans in vast numbers are taking OTC sleep aids frequently and sometimes in addition to prescription sleep aids. The frequency and the additive effects are a potent combination, especially for older Americans.
Most prescription medications for insomnia are either recommended for occasional or limited use, or not recommended for older adults because of adverse outcomes associated with the active ingredient diphenhydramine, an antihistamine mainly used to treat allergies. These outcomes can include cognitive impairment, poor balance and daytime sleepiness.  Their use in older adults has been shown to be problematic at best -- some researchers have shown that diphenhydramine in hospitalized patients is associated with delirium! 
OTC sleep aids with diphenhydramine are also risky for older adults when used for longer than 2-3 days. The fact that diphenhydramine is used more frequently than intended is alarming. A recent study has shown that too much of this drug is associated with increased age and cognitive impairment. As the people in the study aged, prescription medication use remained stable but the use of OTC sleep aids, principally diphenhydramine, increased substantially and this drug in particular was associated with cognitive impairment in persons without dementia. 
The American Geriatrics Society 2012 Beers Criteria for Potentially Inappropriate Medication Use in Older Adults, commonly called the Beers List, includes diphenhydramine as "potentially inappropriate medication and medication that should generally be avoided in older adults," stating that this ingredient is "highly anticholinergic; clearance reduced with advanced age and tolerance develops when used as hypnotic, greater risk of confusion, dry mouth, constipation and other anticholinergic effects and toxicity."  The problem is, the use of OTC sleep aids in older adults is excessive and increasing -- perhaps dangerously so.
A recent health and wellness survey shows that 35 percent of people 60 years or older take OTC sleep medications at least 20 days a month.  And 70 percent of them take OTC pain and sleep combination products, increasing the amount of the active ingredient in their system. This growing practice of self-medicating with OTC sleep products in an off-label way is alarming.
The risks and benefits of OTC sleep aids for the treatment of disturbed sleep in older adults have not been determined. When you add to this the probability that older adults may be taking prescription medications for a host of other age-related ailments, you have a possibly risky, if not deadly, combination. 
What hasn't been done and needs to be done is a careful look at recent findings by sex and gender. Medical investigators need to perform more sex-specific studies. The Ambien experience taught us that women, because they metabolize certain drugs more slowly than men, require a lower dose of the drug. Otherwise, the drug remains in their system long after they awake, potentially placing them at risk for falls, vehicular crashes and other harmful outcomes.
Studies are especially needed on the sex-specific metabolism of diphenhydramine; as of this writing, I could find none. It would not surprise me to learn that women metabolize this drug more slowly as well. That information would be very useful to the vast numbers of women who self-medicate with OTC sleep aids.
This brings up the last point that needs to be made. OTC medications have not received the attention they deserve. Physicians and the public are clearly not having the conversation that needs to take place. Because OTC drugs are so widely available in our homes and being used off-label and more frequently, they should be part of the health care conversation we have with our physicians.
Why hasn't this happened? The reasons are not yet clear. But what is clear is that the public in general, and older women in particular, are taking potentially risky actions by mixing OTC sleep aids with prescription drugs for sleep and other conditions. All for a good night's sleep.
By Christine Carter, PhD, MPH, SWHR vice president of scientific affairs
1. MMWR. 2008;58:1175-1179
2. Sleep: An Essential Component of Health. The Gerontological Society of America. 2013.
3. Mallampalli, MP. Why We Need to Pay More Attention to Women's Sleep. Huffington Post. Posted 6/24/2014. Accessed July 2, 2014. http://www.huffingtonpost.com/michael-keaton/women-sleep_b_5399748.html?view=screen.
4. Albert SM, Bix L et al. Promoting Safe and Effective National Use of OTC Medications: CHPA-GSA National Summit. The Gerontologist. 2014;00(00):1-10
5. Montgomery P, Lilly J. Insomnia in the Elderly. Clin Evid (online). 2007;EPUB.
6. National Institutes of Health. NIH state-of-the-Science Conference Statement on Manifestations and Management of Chronic Insomnia in Adults. June 13-15, 2000. http://consensus.nih.gov/2005/insomniastatement.pdf.
7. Hamblin JE. Insomnia: an ignored health problem. Prim Care Clin Office Pract. 2007;34:659-674.
8. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Institute of Medicine. 2006. http://www.iom.edu/Reports/2006/Sleep-Disorders-and-Sleep-Deprivation-an-unmet-public-health-problem.aspx
9. Tom SE, Martin KR, Spiegel A, Rattinger GB. Presented at SLEEP 2013, the 27th Annual Meeting of the Associated Professional Sleep Societies; June 1-5, 2013; Baltimore, MD.
10. Rothberg MB, Herzig SJ, Pekow PS, et al. J Am Geriatr Soc. 2013;61(6):923-930.
11. Basu R, Dodge H, Stoehr GP, Ganguli M. Am J Geriatr Psychiatry. 2003;11:205-213.
12. Beers Criteria Update Expert Panel. American Geriatrics Society updated Beers Criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2012;60:616-631.
13. Kantar Health, March 2013. National Health and Wellness Survey, 2012 [US], Princeton, NJ.