Why do allergy medications cause drowsiness

Allergy and sinus medications may make you drowsy. A key ingredient in many over-the-counter formulas are antihistamines, which block the body’s production of a natural compound that triggers allergy symptoms. The first generation of antihistamines, which are still widely used, often make people feel sleepy, tired or dizzy.

Can allergy medicine cause drowsiness?

Some drugs used to control allergies can have drowsiness as a side effect. One example is diphenhydramine, a medication that works by blocking histamines, substances in the body that can cause allergic reactions. “It’s a great antihistamine, but it’s an older one, and it has a sedating effect,” Park says.

Why do allergies make you tired?

“So you keep waking up, because you can’t breathe.” Allergy patients may also be tired because of their allergy medicine. Some drugs used to control allergies can have drowsiness as a side effect. One example is diphenhydramine, a medication that works by blocking histamines, substances in the body that can cause allergic reactions.

Why does diphenhydramine cause drowsiness?

Drowsiness is one of the major side effects of some antihistamines, such as diphenhydramine (Benadryl) and doxylamine succinate (the antihistamine found in Nyquil). And because of their powerful sedating qualities, antihistamines are also the active ingredients found in numerous over-the-counter sleep aids.

Why do antihistamines make you drowsy?

Why Do Antihistamines Make You Drowsy? Drowsiness is one of the major side effects of some antihistamines, such as diphenhydramine (Benadryl) and doxylamine succinate (the antihistamine found in Nyquil). And because of their powerful sedating qualities, antihistamines are also the active ingredients found in numerous over-the-counter sleep aids.

Which allergy MED works best?

Benadryl (Diphendyramine) is the best choice here. It has the most evidence for benefit, and works better to reduce swelling and hives than other antihistamines. Chlor-Trimetron (Chlorpheniramine) is a great second line option for allergy symptoms if the second generation antihistamines don’t work well enough.

What are the names of allergy medicines?

Over-the-Counter Allergy Medications. “The most commonly recommended allergy medications are those available over the counter, all of which originally required a prescription. These include Benadryl, Chlor-Trimeton, Claritin, Allegra, Zyrtec, and Flonase,” Hammond said.

Why does diphenhydramine cause drowsiness?

Drowsiness is one of the major side effects of some antihistamines, such as diphenhydramine (Benadryl) and doxylamine succinate (the antihistamine found in Nyquil). And because of their powerful sedating qualities, antihistamines are also the active ingredients found in numerous over-the-counter sleep aids.

Why do antihistamines make you drowsy?

Histamine is a substance released during an allergic attack and can cause drowsiness. Some of the older generation anti-histamine agents (like benedryl) can cause drowsiness because they can pass the “blood brain” barrier and cause a direct effect on thinking. In rare cases in adults, antihistamines can cause agitation.