Is Allegra a Good Antihistamine for Allergies?

Benefits and Side Effects of Allegra for Allergies and Hives

Woman sneezing in tall grass
Colin Hawkins / Getty Images

Is Allegra a good medication for allergies? How does it compare to other allergy medications with regard to efficacy with hay fever and hives, and what are the common side effects? What else should you know before taking Allegra?

Allegra (Fexofenadine) - The Basics

Allegra, also known by the generic name fexofenadine, is an antihistamine medication. Histamine is a chemical messenger released by cells in the immune system to alert the rest of the immune system to a foreign invader.

When that invader is harmless, such as a piece of birch pollen or dust mite, allergy symptoms result. These may include itchy, watery eyes, an itchy, runny nose, and sneezing. When allergy symptoms are moderate to severe and persistent, they can interfere with your ability to work, learn, and play.

Allegra is considered a newer generation antihistamine. First generation antihistamines such as Benadryl (diphenhydramine) and Atarax (hydroxyzine) can be helpful for allergies and hives but their use is limited due to side effects such as fatigue and sedation.

What Conditions May Allegra Be Used For?

Allegra (fexofenadine) is approved for treating the symptoms of:

Dosing and Use in Children

Allegra is available as tablets, liquid, and an orally disintegrating tablet. It can be obtained either by prescription or over-the-counter. If you are alternating between these, make sure to check the doses as they may be different.

Brand name Allegra and generic fexofenadine contain the same active ingredient, but other ingredients (inert ingredients) may differ. These inactive ingredients can sometimes play a role in the absorption of the drug, and some people may notice that either the brand name or generic drug works better for them.

The dosage of Allegra is 15 milligrams twice a day for children 6 months to 2 years of age, 30 milligrams twice a day for 2 to 11 years of age, and 60 milligrams twice a day (or 180 milligrams once a day) for ages 12 years and older. Studies don't support higher dosages for the treatment of hayfever, but higher dosages may be helpful for certain people with hives. Make sure to talk to your doctor before taking a dose higher than recommended on the package or your prescription label.

Do Not Take Allegra With Fruit Juice

If you are taking Allegra, it's important to avoid drinking fruit juice for 1 to 2 hours before you take the medication and 1 to 2 hours after. Juices such as orange juice or grapefruit juice can decrease the absorption of Allegra by nearly half, even juices that only contain 5 percent juice.

How Long Does it Take Allegra to Work?

Allegra starts to work within an hour, so taking Allegra on an as-needed basis can be effective for the treatment of hay fever and hives. Taking Allegra on a daily basis may result in better control of allergy symptoms, however. Studies show that Allegra is nearly as good as Zyrtec at treating hayfever, although Zyrtec (and it's isomer Xyzal) appear to be better medicines for the treatment of hives.

How Does Allegra Compare to Other Antihistamines and Allergy Medications?

Since Allegra can be used in children as young as six months of age, it is sometimes the ideal choice for young children.

How Allegra works in comparison to other medications can vary depending on the severity of your symptoms. In general, medications such as Zyrtec and Xyzal are more effective for controlling the symptoms of allergic rhinitis and hives, but also have a higher incidence of fatigue and sedation.

Common Side Effects with Allegra (Fexofenadine)

Allegra is very well-tolerated and has a low occurrence of side effects.

The most common side effect is a headache, which has been reported to occur in approximately 10 percent of people (with a headache occurring in around 7 percent of people given a placebo.)

Unlike many other antihistamines, Allegra has not been shown to cause a significant amount of sedation or fatigue when compared to placebo, making Allegra a good choice for those who have experienced this symptom with other drugs.

Some people have noted weight gain on antihistamines, though this is probably more likely with the older antihistamines such as Periactin (cyproheptadine.)

Very rarely, more serious reactions, such as Stevens-Johnson syndrome have occurred.

Allergy Treatment During Pregnancy

In general, Allegra should be avoided during pregnancy since the drug is pregnancy category "C" and there are safer medications available (category "B") such as Zyrtec (cetirizine) and Claritin (loratadine.) Allegra should only be used during pregnancy under the guidance of a physician, and then, only if there is a good reason why other (category B) medications cannot be used.

Learn more about the treatment of allergies during pregnancy.

Bottom Line on Using Allegra for Allergies

Allegra (fexofenadine) can be an excellent medication for allergies, but the best choice for any one person is based on the degree of symptom relief desired and the degree of side effects you are willing to tolerate.

For mild to moderate allergy symptoms, Allegra may be preferable to drugs such as Zyrtec since these other drugs are more sedating. Yet, for severe symptoms which are interfering with work, school, or play, a medication such as Zyrtec may be needed.

It is very important to note that every person is different. Despite what studies say, there are many people who do not experience any fatigue on Zyrtec or Xyzal (levocetirizine) and there are people who do experience fatigue on Allegra. If you or your child has allergies which are significant enough to require medication, it's sometimes helpful to try different medications to see which works best for you as an individual. If you try this, talk with your doctor first. It can be very helpful to keep a journal to get an objective measure of which drug works best. For example, you can write down your most annoying symptoms, and rank them from 1 to 10 based on how well they are controlled on the different medications and on different days.

For those who need medications, it's also a very good idea to talk with an allergist about the possibility of allergy testing and allergy shots. While allergy shots require more follow-up (and more pokes) they can sometimes cure allergies (or at least significantly reduce their symptoms) so that medications are no longer needed or allow people to enjoy out-of-door (or indoor) activities much more. In addition, it's thought that allergy shots may sometimes help prevent the development of new allergies.


Continue Reading