Chlorpheniramine Maleate

Chlorpheniramine maleate is an active ingredient found in many prescription medications and over-the-counter products used for treating allergies, hives, and the common cold. As an antihistamine, it works by blocking H1 receptors and acetylcholine receptors in the body. The medication comes in tablet, capsule, and liquid form, and is taken by mouth every 4 to 12 hours, depending on the particular product.

What Is Chlorpheniramine Maleate?

Chlorpheniramine maleate is an antihistamine medication used as an active ingredient in many different non-prescription medicines (such as Chlor-Trimeton^®) and prescription drugs. It is used to treat allergies such as hay fever, hives, and the common cold. Chlorpheniramine maleate is one of the two most common forms of the medication (the other is chlorpheniramine tannate).

(Click What Is Chlorpheniramine Used For? for more information, including possible off-label uses.)

How Does This Drug Work?

Chlorpheniramine maleate is part of a class of drugs called antihistamines. Specifically, it is an H1 receptor antagonist. This means that it blocks a specific type of histamine receptor in the body known as H1 receptors. Since allergic reactions are partly caused by the release of histamine from certain cells in the body, chlorpheniramine maleate can help relieve or prevent allergy symptoms.

Chlorpheniramine maleate also blocks acetylcholine receptors, an action that produces some of the unpleasant side effects of the medication, such as dry mouth or difficulty urinating, but also helps to relieve a runny nose.

(Chlorpheniramine Maleate Continued: Page 2)