Antihistamines — Overview

Why Do Allergies Occur?

About 1/4 of the entire population of America suffers from allergies. We all know what allergies look like:

• Sneezing

• Congestion

• Hives

• Itchiness

If you have allergies, the symptoms you experience are due to the effects of something called histamine. Histamine is a molecule present in our body that is important for creating stomach acid, keeping us awake, as well as regulating our immune system. Histamine is located in something called mast cells which are present all throughout your body.

For example: let’s say you're allergic to cats. Whenever you breath in cat hairs, those go into your body and cause histamine to be released from these mast cells and binds to their receptors, which are called H1 receptors. The binding of histamine to its H1 receptor causes symptoms of allergies like sneezing, runny nose, congestion, itchy eyes, wheezing, upset stomach, and hives.

What Are Antihistamines?

Antihistamines are drugs that BLOCK the binding of histamine to these H1 receptors.

On the market there are first generation antihistamines like Benadryl and second generation antihistamines like Zyrtec and Claritin. Both first and second generation antihistamines bind to the H1 receptor to prevent the actions of histamine to occur

In the next article we'll discuss first generation antihistamines including the name of these medications and the common side effects to watch out for.