Insomnia is a common sleep complaint that affects about 30 percent of adults in the U.S. It occurs when a person has trouble falling asleep or staying asleep, wakes up too early, or feels unrefreshed after sleeping. It causes a variety of daytime problems, including fatigue, moodiness, and anxiety about sleep.
The primary forms of treatment for insomnia are cognitive behavioral therapy (CBT) and prescription medications. Research shows that both of these treatment options can improve the quality and quantity of sleep for people with insomnia.
Many other medications are sold in stores and online for the treatment of insomnia. They can be purchased without a prescription from a doctor. These nonprescription medications are regulated by the FDA as “over-the-counter” (OTC) drugs. FDA-approved OTC sleep aids contain a form of antihistamine as the active ingredient. “Histamine” is a chemical messenger in your brain that promotes wakefulness. Antihistamines typically produce drowsiness by suppressing the activity of histamine.
The FDA permits the sale of OTC sleep aids that contain one of these three types of antihistamine:
- diphenhydramine hydrochloride
- diphenhydramine citrate
- doxylamine succinate
Some OTC sleep aids contain both an antihistamine and a pain reliever.
Studies show that the use of OTC sleep aids is common. In one population survey of 2,181 adults, more than 10 percent of adults said that they used an OTC sleep aid in the past year. Another survey of 3,447 adults found that 21.4 percent of people with daytime problems resulting from insomnia take an OTC medication to help them sleep.
Areas of Concern
More research is needed to determine whether OTC medications produce measurable improvements in sleep. Studies thus far have had small sample sizes and have focused on subjective reports rather than objective measures. Self-reports from patients have shown that OTC medications have helped them fall asleep. The risk involved with long-term use of these products, however, has not been studied.
The antihistamines used in OTC sleep aids can produce side effects such as the following:
- Daytime sleepiness
- Reduced alertness
Daytime drowsiness can be severe in some people who use antihistamines, even when the medication is taken the prior day or night. Some side effects may be stronger in older people. A tolerance to the drug can develop in as little time as three to four days.
Sufficient evidence does not exist to support over-the-counter (OTC) sleep aids as an effective treatment for insomnia. OTC sleep aids that contain antihistamine may provide modest, short-term benefits for adults with mild cases of insomnia. It is important to be aware, however, that the use of antihistamines may produce a variety of side effects.
Important Information Regarding OTC Sleep Aids
- OTC sleep aids that contain antihistamine are approved by the FDA only for “occasional sleeplessness” by people who have trouble “falling asleep.” These products are not intended to be used for more than a few nights or for severe cases of insomnia.
- The information accompanying an OTC sleep aid should be read carefully.
- OTC sleep aids are designed only for bedtime use.
- OTC sleep aids should be taken only as directed by a physician or according to the instructions that come with the medication.
- OTC sleep aids are not intended for use by children under the age of 12.
- OTC sleep aids should not be taken with alcohol or with a sleeping pill, sedative, tranquilizer, or another antihistamine.
- Pregnant or nursing women and individuals with breathing problems or glaucoma should consult their doctor before taking an OTC sleep aid.
- Individuals should consult their doctor if they have either an ongoing problem with insomnia or another sleep problem that affects their daytime activities.
About the AASM
The American Academy of Sleep Medicine (AASM) is the largest professional medical society for clinicians, researchers and other health care providers in the field of sleep medicine. The AASM is committed to promoting excellence in sleep medicine health care, education and research.
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