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.

Is Insomnia a Hybrid State?

Some research suggests that insomnia is a hybrid state, when the brain is neither fully asleep nor fully awake.

Now there’s new evidence for this claim. A new study suggests that insomniacs’ inability to quiet the brain at night is linked to pockets of activity that show up in PET scans while the rest of the brain is asleep.

pet scanSome research suggests that insomnia is a hybrid state, when the brain is neither fully asleep nor fully awake.

Now there’s new evidence for this claim. A University of Pittsburgh study in the October issue of the journal Sleep suggests that insomniacs’ inability to quiet the brain at night is linked to pockets of activity that show up in PET scans while the rest of the brain is asleep.

I was thinking about the implications of this when I went to bed last night. Strange as it may sound, I think it may actually have helped me fall asleep. More about this following news of the study:

Glucose Metabolism During Sleep and Wake

Information processing and thinking require energy. So lots of glucose gets metabolized in the brain during the daytime. Much less glucose is metabolized at night, when the brain is fairly quiet.

The Pitt researchers wanted to assess metabolic activity in the brains of people with and without insomnia to see if there were differences at night and during the daytime. PET scans can measure the rate of metabolic activity occurring in different regions of the brain and render the information in images. So the researchers screened two groups of participants—44 insomniacs and 40 good sleepers—and administered PET scans when they were sleeping and after they woke up.

Summarizing the study results, Daniel Buysse, co-author and professor of psychiatry at the University of Pittsburgh, was quoted in TribLive.com, saying, “What we found is that the people with insomnia have regions of their brain that seem to not shut off as completely when they’re asleep.”

Pitt researchers have been pursuing this line of research for over a decade now. In 2004, results of their first (smaller) neuroimaging study of insomniacs and good sleepers were published, showing similar results.

Regions of Activity and Inactivity in the New Study

Which brain regions were unusually active during sleep? Compared with images of good sleeper brains, the images of insomniacs’ brains during sleep showed significantly higher metabolic activity in 3 key regions associated with

  • Thinking
  • Memory and self-reflection
  • Affect, or mood

This fits pretty neatly with the experience of insomnia, when at night the mind just doesn’t seem to be able to turn itself off. How familiar are thoughts like these: Can I meet my deadline tomorrow? It’s depressing that I handled the presentation so badly. What are they thinking about me now?

Just as interesting was the finding that these same regions of the brain were underactive in insomniacs after they woke up in the morning.

Ever have trouble hauling yourself out of bed? concentrating on your work? feeling low and out of sorts after a bad night’s sleep? Daytime symptoms of insomnia—lack of stamina, trouble thinking, moodiness—may also correspond to the level of metabolic activity occurring in various regions of the brain.

How I Fell Asleep Last Night

When the midnight train whistle sounded I was still engrossed in a novel. But I finally lay down to an internal dialog with myself as I waited to fall asleep:

How’s the spy in the novel going to get back to Viet Nam?

He’s already writing his memoirs in a 3- by 5-foot prison cell. It could get grisly. Bad choice for bedtime reading!

I forgot to read the election news.

Anything but the election! Get back to the character in the book!

I’m too hot. That’s a bad sign.

Throw off a cover, will you!

I might have trouble sleeping.

You’ll fall asleep eventually. You might be partway there.

Hmm.

What if parts of my brain were already asleep? What if at that moment I was experiencing exactly what the neuroimaging studies showed, with parts of my brain already sleeping and other parts resisting sleep? Could I entertain the notion that my brain was halfway released from its burden of consciousness when my mind and senses argued otherwise?

It must have been a comforting proposition. Because after that I was out.

Have you ever had the sensation of being partly awake and partly asleep? What did it feel like?