How Does Diphenhydramine Work As An Antihistamine?

Diphenhydramine belongs to the antihistamine category of medicines. This medicine is a first-generation antihistamine that is used to treat allergies. First-generation antihistamine drugs also have hypnotic effects so they can be used as a sleeping pill by people.

About Diphenhydramine

Diphenhydramine was one of the first antihistamine medicines to be developed in 1943. Allergens affect the body by causing the release of histamine into the body. Histamine causes common symptoms of inflammation, runny noses, and watery eyes. Allergens and the release of histamine can also cause headache and severe allergic reactions can have much more serious conditions involved with them. When having an allergic reaction to anything, it is a good idea to take an antihistamine to control these affects.

History of Diphenhydramine

Diphenhydramine was the first antihistamine to be approved by the Food and Drug Administration in 1946. This drug works as an antihistamine by blocking the histamine receptor sites. When histamine cannot be absorbed by cells, it cannot cause the allergic reactions. Histamines cause fluid to escape from the body's capillaries which is what causes the typical watery eyes and runny noses. When someone takes an antihistamine, these effects are blocked. The antihistamine blocks the histamine receptors on nerves and prevents them from absorbing the histamine released by the body. Diphenhydramine is commonly known as the medication Benadryl.

Effects of Diphenhydramine

In addition to acting as an antihistamine, Diphenhydramine also inhibits the reuptake of serotonin. This means that it can act as a very mild antidepressant, but its real purpose is to be an antihistamine. Like any antihistamine, there are side effects with use of Diphenhydramine. With a first-generation antihistamine, also known as an H1-antihistamine, drowsiness is the number one side effect. This type of antihistamine is the most common and widespread because it is also widely considered to be the most effective. Since Diphenhydramine is an antihistamine that crosses the blood brain barrier, it blocks more histamine receptors than other types.

This medicine can cause severe drowsiness in some people so it is best not to operate vehicles or perform difficult tasks while on one until you know how it affects you individually. Diphenhydramine is commonly sold as a sleep aid and is in many PM medications. Diphenhydramine can relieve itching and restricts the blood vessels in the nose to alleviate a runny nose as well. The medicine works the same way when it comes to the watery eyes. The most common dose of Diphenhydramine for adults is 25-50mg, so take the drug as needed when the symptoms are present.

Diphenhydramine Overview

Diphenhydramine is one of the most common and oldest antihistamine medications in America. It has been proven save to take for over 60 years. Always follow the recommended dosage instructions when using an antihistamine or any other medication. Make sure to be aware of the side effects caused by Diphenhydramine and only take as much as needed. Diphenhydramine can be used with confidence as an antihistamine for its ability to block the histamine receptors in the body. Take as directed and know your limits.