Is it OK to use over-the-counter antihistamines to treat insomnia? I'd like to avoid prescription sleep aids.
Answers from Eric J. Olson, M.D.
Antihistamines can cause drowsiness, which might help you fall asleep for a few nights — but routine use of antihistamines for insomnia isn't recommended.
Antihistamines induce drowsiness by working against histamine, a chemical produced by the central nervous system. In fact, most over-the-counter sleep aids contain antihistamines. These products are intended to be used for only two to three nights at a time, however, such as when stress, travel or other disruptions keep you awake.
Tolerance to the sedative effects of antihistamines can develop quickly. As a result, the longer you take them, the less likely they are to make you sleepy. Side effects might include daytime drowsiness, dry mouth and dizziness.
Also, diphenhydramine and doxylamine — sedating antihistamines often found in over-the-counter sleep aids — aren't recommended for people who have certain conditions, such as closed-angle glaucoma, asthma, chronic obstructive pulmonary disease or severe liver disease.
Diphenhydramine and doxylamine have anticholinergic properties that make them poor choices for older adults. Recent studies have shown that anticholinergics may increase the risk of dementia. These drugs also have numerous side effects in older adults, such as confusion, hallucinations, dry mouth, blurred vision, constipation, nausea, impaired sweating, inability to empty the bladder completely (urinary retention) and rapid heart rate (tachycardia).
Keep in mind that most sleep aids aren't recommended for women who are pregnant or breast-feeding.
If you're struggling with chronic insomnia, don't rely on antihistamines or other over-the-counter sleep aids for a good night's sleep. Start with lifestyle changes instead:
- Follow a regular sleep schedule.
- Avoid caffeine and daytime naps.
- Include physical activity in your daily routine.
- Manage stress.
If you continue to have trouble falling or staying asleep, consult your doctor. In addition to lifestyle changes, your doctor might recommend ways to make your sleeping environment more conducive to sleep or suggest behavior therapy to help you learn new sleep habits. In some cases, short-term use of prescription sleep aids might be recommended as well.
July 13, 2016
- Bonnet MH, et al. Treatment of insomnia. http://www.uptodate.com/home. Accessed Oct. 24, 2014.
- Kryger MH, et al. Principles and Practice of Sleep Medicine. 5th ed. St. Louis, Mo.: Elsevier Saunders; 2011:916.
- Foral P, et al. Insomnia: A therapeutic review for pharmacists. The Consultant Pharmacist. 2011;26:332.
- Chokroverty S, et al. Handbook of Clinical Neurology. 3rd ed. Philadelphia, Pa.: Elsevier; 2011:723.
- Owens JA. Behavioral sleep problems in children. http://www.uptodate.com/home. Accessed Oct. 27, 2014.
- Morgenthaler TI (expert opinion). Mayo Clinic, Rochester, Minn. Nov 10, 2014.
- Gray SL, et al. Cumulative use of strong anticholinergics and incident dementia: A prospective cohort study JAMA Internal Medicine. 2015;175:401.
- Fox C, et al. Anticholinergic medication use and cognitive impairment in the older population: The medical research council cognitive function and ageing study. Journal of the American Geriatric Society. 2011;59:1477.
- Carriere I, et al. Drugs with anticholinergic properties, cognitive decline, and dementia in an elderly general population: The 3-city study. Archives of Internal Medicine. 2009;169:1317.
- Rochon PA. Drug prescribing for older adults. http://www.uptodate.com/home. Accessed July 8, 2016.
- American Geriatrics Society 2015 Updated Beers Criteria for potentially inappropriate medication use in older adults. Journal of the American Geriatric Society. 2015;63:2227.