What You Need to Know About Using An Antihistamine

By Donna Christiano

Some 50 million Americans suffer from allergies each year, reports the American College of Allergy, Asthma and Immunology. That’s an estimated 30 percent of adults and 40 percent of children. And for many of them, their first line of defense is an antihistamine, a drug—available over-the-counter (OTC) or by prescription—that helps prevent the sneezing, sniffling, and watery, itchy eyes triggered by everything from sensitivity to blooming trees and grasses to pet dander.

What exactly are allergies? And how does an antihistamine treat them?

You develop an allergy when your body mistakenly perceives a normally harmless substance—for example, tree pollen, dust, a bee sting, certain foods and even your family pet’s shedding fur and skin—as a foreign substance. Seeing it as an invader, your immune system kicks into overdrive, mounting a defense against it by producing antibodies, which, in turn, trigger the release of a chemical called histamine. It’s histamine that causes the sneezing, runny nose, itchy skin, and watery, itchy eyes that make so many allergy sufferers miserable.

“Think of an antihistamine like duct tape placed over a keyhole,” says Joseph Inglefield, an allergist with the Hickory Allergy, Asthma and Sinus Clinic in Hickory, North Carolina. “It prevents the key from turning on the cells that produce histamine.” 

What types of antihistamines are there?

Your drugstore shelves are lined with antihistamines, most of them coming in the form of pills, liquids, or eye drops (nasal sprays to treat allergies are available, but most of the ones you get OTC contain steroids rather than antihistamines). Your doctor can also prescribe an antihistamine, which is more likely to happen if OTC products aren’t helping or they’re giving you bothersome side effects.

Antihistamines are generally broken down into two categories:

First-generation antihistamines

These are some of the first antihistamines marketed, and, while effective, have the troublesome side effect of making you sleepy—not exactly optimal when you need to be alert for that conference call. So sedating, in fact, are these first-generation antihistamines, that they are sometimes used as sleep aids. Some examples of first-generation antihistamines include:

• diphenhydramine (Benadryl, Nytol, and Sominex) 

• chlorpheniramine (Chlor-Trimeton)

• dimenhydrinate (Dramamine)

Second-generation antihistamines

These are newer antihistamines that differ from their older counterparts in their chemical makeup. They also aren’t nearly as likely to cause drowsiness. Some second-generation antihistamines include:

• fexofenadine (Allegra)

• loratadine (Claritin)

• cetirizine (Zyrtec)

What are the side effects?

Most side effects occur with first-generation antihistamines. In addition to sleepiness, they may cause:

• dry mouth

• feelings of jitteriness, especially in children

• weight gain

• constipation

How should I take an antihistamine?

Use an antihistamine as directed on the package or by your doctor. Many of the second-generation antihistamines last for 12-24 hours, so make sure you’re not taking another dose before you need to. Other considerations:

• Let your doctor and pharmacist know about all OTC or prescription drugs and supplements you take.

• Take an antihistamine before allergy symptoms kick in. For example, if you’re allergic to pollen and the counts have been high in your area, you might take an antihistamine preemptively, before the sneezing and sniffling really start in earnest..

• Don’t take an older antihistamine with a newer one thinking you’ll get double protection. While the two drugs work differently, you may be overmedicating yourself.

• Stick with what you need. Yes, a cold medication or sleep aid may contain an antihistamine, but it will also likely have other ingredients you don’t necessarily need or want. 

Who shouldn’t take antihistamines?

According to the American Academy of Family Physicians, certain people should consult with their doctors before taking an antihistamine. They include people with:

• heart disease

• high blood pressure

• asthma and other breathing problems

• urination problems

• thyroid issues

• kidney disease

• liver disease

Children and the elderly should also proceed with caution, as they can be more sensitive to an antihistamine’s (or really any medication’s) side effects.

How to save on commonly used antihistamines

Prices for antihistamines vary according to the type and quantity and whether they’re sold via  prescription or OTC, among other things. Regardless, though, you can always save with your FamilyWize discount card. 

   Drug                             Quantity Cash price      Family Wize discount price