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Sleep Aids And Stimulants (cont.)

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What over-the-counter (OTC) medicines are there for insomnia?

Self-treatment of insomnia with over-the-counter (OTC) drugs is advisable only for transient or short-term insomnia. OTC sleep aids should only be used for a short period of time in conjunction with changes in sleeping habits. Chronic use of these drugs may result in dependence on them. This creates a situation in which sleep is not possible unless the drug is used. Chronic insomnia should be evaluated by a physician.


Diphenhydramine (for example, Sominex, Nytol) and doxylamine (for example, Unisom) are antihistamines currently marketed as OTC sleep aids. Diphenhydramine is the only agent considered to be safe and effective by the Food and Drug Administration. Other uses for diphenhydramine include allergies, motion sickness, and cough suppression. Scientists believe that diphenhydramine and doxylamine cause sedation by blocking the action of histamine in the brain, but the exact mechanism of action is not known.

If insomnia is associated with pain, there are numerous products containing a combination of an antihistamine and pain reliever. These combination products should not be used if pain is not present because the added pain reliever is not necessary.

Pregnancy and lactation: The effects of diphenhydramine and doxylamine on the fetus have not been evaluated adequately. Diphenhydramine  is classified as a pregnancy "category B" drug, and is routinely safely used during pregnancy. Although the likelihood of an adverse effect on the fetus is low, sleeping agents probably should be avoided during pregnancy. Both agents may decrease lactation (production of milk). Additionally, these drugs are secreted into the breast milk, which could affect the newborn. Nursing mothers should avoid both drugs. Consult a physician if you are pregnant and have insomnia.

Children: Children less than 12 years of age should not use doxylamine because its use in this in age group has not been assessed.

Elderly: Sedative effects of these drugs may interact with other potentially sedating medications. Consult a doctor before using these drugs.

Drug interactions: Diphenhydramine and doxylamine add to the sedative effects of alcohol and other medications that cause drowsiness.

Side effects: Drowsiness is the most frequent side effect of both diphenhydramine and doxylamine. These agents should not be used in situations where mental alertness is required (for example, driving). Diphenhydramine and doxylamine also cause constipation, dry mouth, and difficulty urinating. Both drugs may worsen the symptoms of glaucoma, asthma, heart problems, and prostate gland enlargement. People with these conditions should not use OTC sleep aids without consulting a physician.

Both drugs may paradoxically cause excitation, resulting in nervousness and insomnia. This occurs most often in children and the elderly.

Medically Reviewed by a Doctor on 11/20/2015


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