Sleeping Pills: What You Need to Know

From dependency risks to a.m. drowsiness, not all sleep aids work alike. Which is right for you?

Medically Reviewed by Celia E. Dominguez, MD
6 min read

Time-crunched by work, play, and family, Americans are getting less sleep than ever. TV commercials promise a good night's rest that's as close as the medicine cabinet, and millions take over-the-counter and prescription aids to help them sleep.

Taken properly, sleeping pills give enormous benefit to people suffering from an inability to get restful sleep. At the same time, the rise in the use of sleep medication has been accompanied by reports of abuse and unpleasant side effects.

How do these medicines work on the brain and in the body? What are the side effects to look for -- and what about the risk of dependence? We talked to the experts to get insights into sleeping pills: everything from A to (your) Z's. If you're taking a sleep aid, or think you should, here's what you need to know.

All sleep medications work on the brain to promote drowsiness. Some drugs are specially designed as sleep aids; others are medicines with sedation as a side effect.

The guide that follows includes most commonly used sleeping pills. Remember, talk to your doctor before you use a sleep aid.

Diphenhydramine is an over-the-counter medicine commonly taken for allergy symptoms. One of its side effects is drowsiness, and for this reason diphenhydramine is often used as a sleep aid. Many of the most popular over-the-counter sleep aids contain diphenhydramine:

Diphenhydramine helps those with mild, infrequent insomnia. For someone with persistent insomnia, however, "it's not a very good drug," according to Milton Erman, MD, clinical professor of psychiatry at the University of California, San Diego. "Very little data show that it helps people get good sleep."

Diphenhydramine can also cause unwanted sleepiness in the morning, according to Susan Esther, MD, member of the board of directors of the National Sleep Foundation.

Other side effects of diphenhydramine include:

  • Difficulty urinating
  • Confusion or delirium

These occur most in people over 65, who should avoid taking diphenhydramine. Younger people shouldn't take diphenhydramine for more than two weeks, because tolerance can develop.

Selective Gamma-aminobutyric acid (GABA) medications are among the newest sleep medicines and include:

These sleeping pills work on the GABA receptors in the brain, which help control our level of alertness or relaxation.

The selective GABA medications target only a certain type of GABA receptor, one believed to be more dedicated to promoting sleep.

"They're more rapid in onset, more selective in their action, and less prone to side effects," says Arthur Spielman, PhD, professor of psychology at the City College of the City University of New York. In most people, selective GABA medicines are metabolized completely before morning.

Because selective GABA medicines don't work on all the GABA receptors throughout the brain, "they are thought to be relatively safer" than benzodiazepines, the older drugs on which they're based, "with less addictive potential," says Esther.

However, selective GABA medicines do have potential side effects, which are usually mild and include:

Ambien and other medicines in this class have also been blamed for episodes of "confusional arousal" -- what most of us would call sleepwalking. In a few well-publicized cases, people drove cars or wandered away from home after taking the drugs. These cases represent only a tiny percentage of the number of people who have taken these medicines, however.

Sleep-wake cycle modifiers:Ramelteon (Rozerem) is the newest prescription sleep medicine, and the only drug in its class. Ramelteon acts directly on the body's sleep-wake cycle, or circadian rhythm.

The sleep-wake cycle is partially controlled by a part of the brain called the hypothalamus. Ramelteon binds specifically to melatonin receptors in this "circadian clock" area of the brain, promoting sleep. "This might be good for a 'night owl' trying to get to sleep for a new job," says Esther.

Because its activity is limited to one part of the brain, ramelteon has few side effects compared to other medicines that act more generally. Its risk of physical dependence is thought to be essentially zero. However, all sleep medicines can cause psychological dependence.

Ramelteon also does not seem to have any potential for abuse, so it is not controlled like benzodiazepines and selective GABA medicines such as Ambien, Lunesta, or Sonata. So far, it has not been shown to cause hallucinations or sleepwalking.

Studies show that ramelteon works well in older adults with chronic insomnia. Because it acts on a part of the brain that controls hormones, ramelteon may affect hormone levels if taken for extended periods. This can reduce sex drive in men or make it harder for women to get pregnant.

Benzodiazepines are older medicines that effectively help people get to sleep, and were previously the most commonly used sleep medicines. Drugs in the benzodiazepine class include:

Benzodiazepines activate GABA receptors in the brain, causing sedation and relaxation and promoting sleep. Because they act on various types of GABA receptors throughout the brain, though, benzodiazepines have other effects:

  • Reduced anxiety
  • Muscle relaxation
  • Poor memory of some events while taking the drug
  • Euphoria

Benzodiazepines are only available by prescription. While they are sometimes the right medicine, benzodiazepines should be used with caution:

  • People who take benzodiazepines regularly may develop tolerance, or even a physical dependence on the drug (addiction).
  • Benzodiazepines have a relatively high potential for abuse.
  • They are not appropriate for long-term use.

"You wouldn't want to use them more than a few days," or longer in rare cases, according to Esther.

These days, physicians prescribe benzodiazepines infrequently, because newer medicines generally work as well without as much potential for abuse or dependence.

Physicians usually prescribe tricyclic antidepressants, called TCAs, for depression or chronic pain. TCAs include:

For people with depression or chronic pain who also suffer from insomnia, TCAs may play a role in treatment. But because they act throughout the brain, tricyclic antidepressants can have pronounced side effects:

The lower doses used for treatment of insomnia tend to reduce these effects. These medicines can be useful for "someone who has failed better agents or is anxious about the other medicines," says Erman.

Experts agree that while sleeping pills can be an important and necessary part of a successful sleep program, they can't be the only answer.

"Medicines can be helpful, but they shouldn't be a quick fix," says Esther. "They need to be part of a balanced plan of habits and common sense."

According to the National Sleep Foundation and others, good sleep habits should include:

  • No caffeine later in the day
  • Avoid nicotine or alcohol two to three hours before bedtime.
  • Use your bedroom only for sleeping and sex.
  • Maintain a regular sleep-wake schedule on all days, including weekends.
  • Exercise regularly but complete it several hours before bedtime.
  • Finish eating at least 2-3 hours before bedtime
  • Create a restful sleep environment by reducing noise, light, and temperature extremes with ear plugs, window blinds, an electric blanket, or air conditioner.

All sleep medicines have the potential to cause dependence, according to sleep experts. Dependence means not being able to stop taking the drug without problems. Nearly always, this is a psychological dependence.

According to Erman, "If you're used to taking the drug to sleep, going without it will make you anxious, and in fact, unable to sleep"-- even though you're not physically dependent on the medicine.

If you feel you're dependent on a sleep medicine, see your doctor. They will address the problem with you. Your doctor may refer you to a sleep specialist.

Taking benzodiazepines regularly can lead to a physical tolerance and dependence, or addiction. If you've been taking these medicines for a prolonged period, do not stop abruptly. See your doctor and work out a schedule to stop taking them safely.