If You Take This Common Medication to Sleep, Stop Now, New Study Says

While these OTC meds are often taken for insomnia, they have scary side effects.

When you're struggling to fall asleep, you'll take just about anything to help you snooze. However, just because a medication can help you sleep doesn't necessarily mean you should take it for that purpose. A recent study noted that a common medication that is often used to help people fall asleep can actually have significant adverse side effects. Read on to find out which popular medication you should stop taking to help you sleep, and for a medication that could be keeping you up, If You Can't Sleep, This OTC Medication Could Be Why, Experts Say.

Don't use antihistamines to help you sleep.

person removing pill from medication blister pack into hand

As an April 6 paper out of McMaster University published in the Canadian Medical Association Journal noted, "Antihistamines are among the most commonly and incorrectly used medicines worldwide." While antihistamines are recommended to address the symptoms of hay fever and outbreaks of hives, they have other off label-uses, including for insomnia, according to the paper. Benadryl, ZzzQuil, Tylenol PM, Dramamine, Unisom, and many other over-the-counter (OTC) sleep medications include antihistamines. The recent McMaster University paper made a case for avoiding the use of these medications for treating anything other than hay fever or hives.

Harvard University reported that in 2017, the American Academy of Sleep Medicine (AASM) officially recommended against treating chronic insomnia with common OTC antihistamine-based medications due to a lack of evidence for their efficacy or safety. "There are definite concerns about their risks," said Suzanne Bertisch, MD, an assistant professor of medicine at Harvard Medical School, said in an article on the university website. And for more potential dangers in your medicine cabinet, The FDA Just Issued a New Warning About These OTC Pain Meds.

Taking antihistamines for sleep can cause adverse side effects.

Middle age woman with fatigue
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Although your OTC antihistamine medication may do the trick and help you fall asleep faster, it could cause adverse effects. The McMaster University paper noted that antihistamines can affect cognitive functions, such as school or work performance, and an overdose can even lead to death. According to the Baylor College of Medicine, "Antihistamines have side effects that include altered mental state, urinary retention, and dry mouth. While these side effects are generally mild and well tolerated in young patients without other medical problems, they can pose a risk, especially for the elderly."

Additionally, the antihistamines you're taking to improve your sleep may ultimately have the opposite effect. "Use of antihistamines can lead to sleepwalking and other parasomnias. That can definitely occur with Benadryl just as with other hypnotic agents like Ambien," assistant professor of medicine Phillip Alapat, MD, said in an article on the Baylor College of Medicine website. Although antihistamines may help you fall asleep, the overall quality of sleep is often not very good, and the medication has its limits. "Using Benadryl or any antihistamine for sleep has no long-term benefit," Alapat continued. "Most people develop a tolerance very quickly." And to make sure you're staying safe, If You're Taking Tylenol With This, Your Liver Is in Danger, Experts Say.

Newer antihistamines are less risky.

Close up young woman pouring pills out of bottle. Stressed millennial student holding aspirin painkiller antidepressant antibiotic to relieve pain, feeling unhealthy at home or office.

Not all antihistamines are the same, however. The paper from McMaster University noted that first-generation antihistamines are the ones to worry about, while newer antihistamines are generally safer. Benadryl, ZzzQuil, Tylenol PM, Dramamine, Unisom, and many OTC sleep medications contain first-generation antihistamines, while allergy medications like Zyrtec, Claritin, and Allegra, on the other hand, contain second-generation antihistamines.

The McMaster University paper noted that later-generation antihistamines are safer while also being more effective and just as affordable as first-generation antihistamines. The newer antihistamines also have fewer side effects, such as drowsiness, which means they likely would not aid sleep. And for more useful information delivered straight to your inbox, sign up for our daily newsletter.

Antihistamines should also not be used for asthma, eczema, or cough.

Shot of a young man taking medication while standing at home during the day.

Antihistamines are also used off-label to address asthma, eczema, and coughing, but that's not what they're meant for. "People need to rethink what they stock in their home cabinets as allergy medicines, what hospitals keep on formulary, and what policymakers recommend. The message needs to get out," McMaster University allergy expert and clinical scholar Derek Chu said in a statement.

"Antihistamines are best used to relieve symptoms of hay fever and outbreaks of hives, but not for asthma, eczema, coughs, or insomnia," the statement concluded. So the next time you find yourself reaching for that bottle of Benadryl as a cure-all, think again. And for more advice on the medications you should and shouldn't be taking, This Is When You Should Take Tylenol Instead of Advil, Doctors Say.

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