Use OTC Sleep Aids With Caution

The sleeping pill of choice for many Americans with insomnia can be purchased over the counter at drug and grocery stores. But a new study shows that many older adults who use OTC sleep aids know little about them and may be using them in ways that do more harm than good.

Sleeping pill users should read the label of OTC sleep medicationsIt annoys me when people dismiss sleeping pills as categorically harmful. Yes, they can be used inappropriately and it’s important to be informed about their downsides. But the existence of downsides doesn’t necessarily mean the risks associated with using them outweigh the benefits.

The sleeping pill of choice for many Americans with insomnia can be purchased over the counter at drug and grocery stores. But a new study shows that many older adults who use OTC sleep aids know little about them and may be using them in ways that do more harm than good.

Older Americans Use Them and Like Them

Participants in the new study were adults in the United States aged 60 and older who were managing their sleep problems with nonprescription sleep aids. University of Pittsburgh investigators interviewed 116 by telephone and found that well over half were satisfied with their medication and felt it improved their sleep.

Asked about her satisfaction with one such drug, an interviewee replied that she was “pretty satisfied. It does help me fall asleep and stay asleep, and go back to sleep when I invariably get up once or twice a night.”

“There is a dramatic difference when I use it versus when I don’t,” another explained.

This jibes with the results of other, quantitative research. The prevalence of insomnia and other sleep problems among older adults is high and OTC sleep aids are widely available. About 17% of older adults in the United States turn for relief to antihistamine-containing sleep aids like Unisom and Simply Sleep.

How OTC Sleep Aids Work

Diphenhydramine and doxylamine are the active ingredients in antihistamine sleep aids. They block the action of histamine neurons, which are generally active when we’re awake and inactive when we’re asleep.

“Marked drowsiness may occur,” is the type of warning that usually appears on the label. This propensity to cause sedation is likely why, despite few controlled trials supporting their efficacy for insomnia, these drugs are seen as effective by many older adults. The trials that have been conducted suggest these antihistamine sleep aids may have more to offer sleep maintenance insomniacs than people who need help falling asleep at the beginning of the night.

Side Effects of OTC Sleep Aids

But like most prescription medications, OTC sleep aids are not intended for nightly or long-term use. Continuous use has been found to lead to the development of tolerance, tempting users to take more of the drug to get the same sedative effect. Yet in the Pittsburgh study, nearly half of the participants reported using OTC sleep meds daily or very often. Over half reported using them for more than a year.

Fewer than a quarter of the study participants had studied the label on their medication to find out about the recommended dosage or about warnings and possible side effects.

“I never really paid any attention to the directions,” an interviewee said. “I take a couple before I go to bed, about twenty minutes before I go to sleep, I go upstairs and go to bed. That’s it.”

Common side effects to be aware of are morning grogginess (our bodies process drugs more slowly as we age) and blurred vision, constipation, and trouble urinating (for more on this, see my post on OTC sleep aids and anticholinergic effects).

Drug-Drug Interactions

Possible drug-drug interactions is another factor to take into account, given that almost 40% of older Americans are taking five or more prescription medications. Studies have shown that diphenhydramine (the main ingredient in many OTC sleep aids, including Benadryl, Sominex, Nytol, ZzzQuil, and Simply Sleep) interferes with the body’s metabolizing of at least three commonly prescribed drugs:

  1. tamoxifen, an anti-estrogen drug used to treat breast cancer and lower breast cancer risk
  2. metoprolol (Lopressor), a beta blocker used to treat high blood pressure and heart problems
  3. venlafaxine (Effexor), a selective serotonin and norepinephrine reuptake inhibitor (SSNRI) used to treat depression

Reducing the effectiveness of a drug taken to manage a serious health condition isn’t something most of us would want to do. But information about all possible drug-drug interactions isn’t necessarily listed on the label of OTC sleep aids.

Americans seem to have the attitude that OTC meds are harmless—but that isn’t necessarily true. If you’re going to use an OTC sleeping pill, read the label for information about the proper dosage and potential side effects. Take concerns about possible drug-drug interactions to your doctor or pharmacist.

Over-the-Counter Sleep Aids Aren’t Harmless

Americans love over-the-counter (OTC) sleep aids. In 2015 we spent $427 million on products like ZzzQuil, Unisom, and Sominex.

These drugs are advertised “for relief of occasional sleeplessness.” Yet many Americans—particularly older adults—use OTC sleep aids several nights a week and may want to consider scaling back because of the side effects.

Older insomniacs may want to scale back on use of over-the-counter sleeping pillsAmericans love over-the-counter (OTC) sleep aids. In 2015 we spent $427 million on products like ZzzQuil, Unisom, and Sominex.

These drugs are advertised “for relief of occasional sleeplessness.” Yet many Americans—particularly older adults—use OTC sleep aids several nights a week and may want to consider scaling back because of the side effects.

Why So Popular?

Some long-time insomnia sufferers are quick to dismiss OTC sleeping pills as worthless.

“They’re like nothing burgers to me,” said Melissa, a lifelong insomniac I interviewed for my book.

Others say these drugs help them sleep. Research does indicate that the active ingredient in these medications—diphenhydramine or doxylamine—has a sedative effect. All of these first generation antihistamine drugs block secretion of histamine, a neurotransmitter associated with wakefulness.

Other factors accounting for the popularity of OTC sleep aids include their ready availability and relatively low cost; the widespread belief in the safety of OTC medications in general; and the fact that insomnia is such a common problem.

Why Such Mixed Appeal?

There’s no clear explanation for their mixed appeal among people with insomnia.    

“The problem is that there is not a whole lot of research on these medications,” said Dr. David Neubauer, associate professor of psychiatry at Johns Hopkins University School of Medicine and associate director at the Johns Hopkins Sleep Disorder Center, in a Medscape program on insomnia aired a few years ago. “Not much efficacy support exists.”

Labels on some of these sleep aids state that the product “reduces the time it takes to fall asleep if you have difficulty falling asleep.” But results of the few studies conducted in recent years do not back this claim up. Diphenhydramine has not been shown to put people to sleep any faster than placebo.

So sleep onset insomniacs—those whose sleep problem occurs at the beginning of the night—may not have much luck with OTC sleep aids.

Sleep maintenance insomniacs—those with trouble staying asleep—may fare a little better. A small amount of evidence suggests that diphenhydramine can reduce the number of nighttime wake-ups and improve sleep efficiency.

Dependency and Tolerance

Drug companies promote these sleep aids as “non-habit forming.” The fact that they can be purchased without a prescription indicates that healthcare professionals evaluating diphenhydramine and doxylamine for the FDA felt the risk of developing a dependency was low.

But tolerance to the drugs may build up if they’re used too frequently. Research suggests that if you take them every night, you’ll wind up needing to increase the dose to get the same sedative effect.

Long-Lasting Sedative Effects

Another problem with these antihistamines is that their sedative effects are fairly long lasting. “The elimination half-life is relatively long, so patients often experience morning grogginess,” Neubauer said. (Half-life is the time it takes for a dose of a drug in the blood plasma to decrease by half.)

Diphenhydramine has a half-life of 2.4 to 9.3 hours, and its half-life tends to increase with users’ age. The half-life of doxylamine is about 10 hours and may be longer in older adults. Morning grogginess increases the risk of falls and driving incidents.

“Dirty” Drugs

The other big problem with these OTC sleeping pills is their many nasty side effects.

“Most problematic would be the potential for anticholinergic effects,” Neubauer said. Common anticholinergic effects include blurred vision, constipation, decreased sweating, dizziness, dry mouth, and difficulty urinating and/or kidney failure.

“If people are taking too much of these medications or taking them in conjunction with other medications that might have anticholinergic effects, they can have side effects like delirium, confusion, dry mouth, or constipation. I have seen people with complete urinary retention caused by adding some diphenhydramine to their medication regimen to try to sleep better,” Neubauer said.

Anticholinergic drugs also put users at increased risk of developing dementia.

How Much Is Too Much?

The warnings I see in the literature these days are mainly directed at older adults, whose bodies process drugs more slowly and who are also more likely to be taking other anticholinergic drugs.

“Older adults are more likely to take diphenhydramine or doxylamine products 15 or more days in a month, an indicator of inappropriate use,” state the authors of a paper on the use of OTC sleep aids in older adults.

These authors are speaking to fellow physicians—but older adults who use these medications should also take note. It may be time to pull back on use of OTC sleep aids and look for other ways to get a good night’s sleep.

OTC Sleep Aids: A Risky Business

Many of us assume that over-the-counter drugs are safer than prescription drugs.

Yet the long-term effects of any drug can remain unknown for decades, and now researchers have found a correlation between long-term and/or high-dose use of OTC sleep aids and dementia.

Over-the-counter sleeping pills may not be as safe as we thinkSome insomniacs are leery of prescription sleeping pills but feel OK about sleep aids sold at the drugstore.

“I’m not really looking for medical intervention,” said Dale, a marketing manager who spoke to me about his insomnia as I was conducting interviews for my book. “I’m absolutely not interested in anything strong. But if it’s sold over the counter and I can take a half dose of it, that’s fine.”

Many of us assume that over-the-counter drugs are safer than prescription drugs. Yet the long-term effects of any drug can remain unknown for decades, and now researchers have found a correlation between long-term and/or high-dose use of OTC sleep aids and dementia.

Which Drugs Are Involved?

These drugs are called anticholinergics, among them the first-generation antihistamines that are now marketed as sleep aids. The active ingredient in these sleep aids is diphenhydramine or doxylamine. Here’s a list of common brand names:

  • Benadryl
  • Sominex
  • ZzzQuil
  • Tylenol PM
  • Excedrin PM
  • Nytol
  • Unisom
  • Store brands containing diphenhydramine and doxylamine.

Anticholinergic drugs block the action of acetylcholine, a neurotransmitter that plays an important role in waking us up and keeping us vigilant. When we’re awake, acetylcholine neurons are active in several areas of the brain. But the brains of people with Alzheimer’s disease show a marked reduction of acetylcholine and acetylcholine-secreting nerve cells. Other common anticholinergic medications include tricyclic antidepressants such as doxepin (Sinequan) and antimuscarinic drugs for bladder control such as oxybutynin (Ditropan).

Gist of the Study

Investigators at the University of Washington began tracking the medical records of 3,434 healthy 65-year-olds to see if anticholinergic medications increased their risk of developing dementia. About 23 percent of these older adults went on to develop dementia over a 7-year period.

Compared with people who did not take anticholinergic drugs, people taking at least 4 mg of diphenhydramine daily (1 capsule of Benadryl or ZzzQuil contains 25 mg of diphenhydramine), 10 mg of doxepin daily, and 5mg of oxybutynin for more than 3 years had a small increased risk of developing dementia. The risk increased in a linear fashion with higher doses and longer use.

Results in Perspective

This is not the first study to link dementia to the use of anticholinergic drugs. Researchers in Australia found that taking more anticholinergic medications was associated with greater risk of hospitalization for confusion or dementia. Researchers in Spain have concluded that long-term use of anticholinergic drugs “may generate a worsening of cognitive functions” and can also “initiate signs of dementia.”

None of the studies show that the relationship between anticholinergics and dementia is causal. Yet they do suggest that frequent use of OTC sleep aids may not be as harmless as many insomniacs suppose.

So what to do? Several prescription sleeping pills have also been connected to an increased risk of dementia, and a small body of research suggests that poor sleep may itself be a factor in the development of cognitive impairment. Now is the time to check into drug-free treatments for insomnia and be more sparing in the use of sleep meds, whether they’re handed over by a pharmacist or you can buy them right off the shelf.

 

The Low-Down on OTC Sleep Aids

Over-the-counter sleeping pills are readily available at the pharmacy: drugs like ZzzQuil, Benadryl, Unisom and Tylenol PM. All promise sound, refreshing sleep. Just how well do live up to that promise, and are they as harmless as they’re said to be?

OTC-sleep-aidOver-the-counter sleeping pills are readily available at the pharmacy: drugs like ZzzQuil, Benadryl, Unisom and Tylenol PM. All promise sound, refreshing sleep. Just how well do live up to that promise, and are they as harmless as they’re said to be?

These sleep aids work by blocking the secretion of histamine, a neurotransmitter that keeps you awake. Nearly every insomnia sufferer I know has tried them at some time or another, and some are satisfied customers.

“Whatever’s in Unisom, I’ve found it works for me pretty well,” says Dale, a marketing expert I interviewed for my book, whose main problem is getting to sleep at the beginning of the night and who sometimes wakes up in the middle of the night. “It’s 80 to 90 percent reliable.”

Other people with insomnia dismiss over-the-counter sleep aids as worthless. Existing scientific research suggests their efficacy is indeed fairly limited.

The active ingredient in most OTC sleeping pills is diphenhydramine (some formulations of Unisom contain doxylamine, a similar drug). In one study, diphenhydramine moderately increased subjects’ sleep efficiency (i.e., they spent more of their time in bed sleeping rather than lying awake).* In another study, older insomniacs taking the drug woke up a little less frequently at night.** Pretty small gains. Yet what behaves like a sugar pill for one insomniac can apparently work magic for another.

Downsides of OTC Sleep Aids

You might think, because these drugs are sold over the counter, that you can use them however you see fit without risk. Some are advertised as “non-habit-forming.” But here it’s better to be cautious. Studies suggest that if you take them every night, you’ll wind up needing to increase the dose to get the same sedative effect.

“Over-the-counter antihistamines may have a role for short-term insomnia treatment in younger adults,” write the authors of a review paper published last year, “but tolerance develops rapidly.”*** So nightly use of OTC sleep aids is not a good idea.

Lingering Effects

The other problem with these antihistamines is that their sedative effects are relatively long lasting and can cause morning drowsiness. Compared to newer prescription sleep meds, they have long elimination half-lives. (Half-life is the time it takes for a dose of a drug in the blood plasma to decrease by half.)

Diphenhydramine has a half-life of 2.4 to 9.3 hours, and its half-life tends to increase with users’ age. It will leave some people—older adults, especially—feeling groggy in the morning. The half-life of doxylamine is about 10 hours, and typically longer in older adults. It, too, may cause morning drowsiness, which increases the risk of falls and driving incidents.

Dale has found a way to cut down on the grogginess. “I use half the recommended dosage,” he says. “That minimizes the hangover in the morning.”

If you’re using OTC sleep aids, keep these caveats in mind.

*    Valerian-hops and Diphenhydramine

**  Temazepam and Diphenhydramine

*** Histamine-1 receptor antagonism