See the DrugPatentWatch profile for doxylamine
What does doxylamine do in the body?
Doxylamine is an antihistamine. It blocks the body’s histamine-1 (H1) receptors, which helps reduce allergic-type symptoms and also makes it cause drowsiness in many people. [1]
Because it crosses into the brain and acts as a sedating antihistamine, doxylamine is commonly used for short-term sleep problems. [1]
How does doxylamine affect allergy symptoms?
By blocking H1 receptors, doxylamine can lessen symptoms such as:
- runny nose and sneezing
- itching or hives (depending on the product and indication)
- watery eyes
Its main mechanism is antihistamine (H1-blocking), which reduces the effects of histamine released during allergies. [1]
Why is doxylamine used for sleep?
Doxylamine’s H1-blocking action in the brain can produce sedation. That sedating effect is why it’s used in some over-the-counter sleep formulations. [1]
What side effects happen because it is sedating and antihistamine-like?
The same H1-blocking and sedating effects can lead to common antihistamine side effects, such as:
- daytime drowsiness or fatigue
- dry mouth
- constipation
- blurred vision
These effects are typical of sedating, first-generation antihistamines. [1]
Is doxylamine the same as other antihistamines?
Doxylamine is a first-generation antihistamine, which usually means it is more likely to cause drowsiness than newer (second-generation) antihistamines. [1]
Sources
- https://www.drugs.com/doxylamine.html