May 20, 2022

Antihistamines and sleep: can you take an antihistamine every night?


A good night’s sleep is essential for your health. So when you stay awake at 1 a.m. for the third night in a row, you might be tempted to rest any way you can, with everything in your medicine cabinet. Most often this means an antihistamine that warns of drowsiness on the box or you know anecdotally makes you crack. So how bad is it really? Here’s what you need to know about taking an antihistamine to fall asleep.

The main ingredient in this fast-acting antihistamine is diphenhydramine hydrochloride (DPH).

It is the active ingredient in Benadryl, an antihistamine used to treat the symptoms of a allergic reaction like itching, watery eyes and sneezing. The sleeping part is actually just a side effect shown on the box.

Histamine is a chemical that produces the inflammatory response behind allergy symptoms, but it also plays a key role in promote awakening. (The nature of this relationship is not well understood.) So in addition to soothing allergy symptoms, when antihistamines neutralize histamine in your body, they have the side effect of making you feel tired, Rafael Pelayo, MD, a sleep specialist at the Stanford Sleep Medicine Center, tells SELF.

But this ingredient won’t necessarily knock everyone out. David Rapoport, MD, director of the Sleep Medicine Research Program and professor of pulmonary and sleep medicine at Icahn School of Medicine in Mount Sinai, told SELF that these drugs are not very potent as sleeping pills. A 2017 review of research in the Clinical practice guidelines for the pharmacological treatment of chronic insomnia in adults reviewed 46 studies with the aim of recommending clinical guidelines for the treatment of insomnia. The researchers determined that the evidence behind DPH drugs leading to better sleep was “clinically insignificant,” suggesting that people should not try using these drugs to fall asleep faster or stay asleep longer.

However, as Dr Pelayo points out, the way you respond to a certain medicine is quite individual, and you may react more strongly due to the placebo effect of taking something that you think will help you. will make you drowsy.

Here’s what doctors think about using DPH to help you fall asleep.

“It’s very appealing to people because it’s an over-the-counter drug,” says Dr. Rapoport. “His [seen as] a quick and dirty way to fix your insomnia.

But, okay, how bad is that? DPH is generally very safe and comes with a low risk of serious side effects, so it’s not that bad if you turn to it to help you relax every now and then, says Dr Rapoport. But there are a few things doctors want you to know first.

“The big problem with this type of drug is that it lasts long enough in your system,” says Dr. Pelayo. The lingering effect of a standard adult dose (25 to 50 milligrams, i.e. one to two tablets or liquid doses) probably won’t be incredibly strong, says Dr. Rapoport, but it may be enough to get you. feeling drowsy or foggy. the next morning. Other side effects are mild and may include dry mouth, nose and throat; dizziness, constipation; headache; and nausea, depending on the National Institutes of Health (NIH).