Sleeping Pills: What You Need to Know

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.

How Sleep Aids Work

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.

Sleeping Pills for Mild Insomnia

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:

• Excedrin PM
• Nytol
• Tylenol PM

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.

Common Prescription Sleep Aids

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

• Ambien (zolpidem tartrate)
• Ambien CR (zolpidem tartrate extended release)
• Lunesta (eszopiclone)
• Sonata (zaleplon)

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.