logoThe People's Perspective on Medicine



Allegra is a relatively new nonsedating antihistamine used to treat allergies such as hay fever. It alleviates symptoms such as runny nose, itchy, watery eyes and sneezing.

Allegra was actually developed from a metabolite of Seldane. It is supposed to provide the anti-allergy benefits without the heart rhythm disturbances that can make Seldane hazardous.

Side Effects and Interactions

Side effects of Allegra are uncommon, but in studies 2.5% of the volunteers on Allegra came down with a cold or the flu.

Other reactions they reported included indigestion, menstrual cramps, fatigue and, in a few people, drowsiness. Report any symptoms to the physician promptly.

Both erythromycin and Nizoral can change blood levels of Allegra, making them go higher and last longer. But because Allegra does not seem to affect the heart, no negative results have been noted.

As more information accumulates on this new medication, further interactions may be uncovered.

Check with your pharmacist and physician to make sure Allegra is safe in combination with any other drugs you take.

Special Precautions

People with kidney problems may not eliminate Allegra efficiently and may need a lower dose.

Taking the Medicine

Allegra is taken two times a day. The capsules should be kept at room temperature and away from moisture.

Rate this article
1.5- 2 ratings
About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
Tired of the ads on our website?

Now you can browse our website completely ad-free for just $5 / month. Stay up to date on breaking health news and support our work without the distraction of advertisements.

Browse our website ad-free
Join over 150,000 Subscribers at The People's Pharmacy

We're empowering you to make wise decisions about your own health, by providing you with essential health information about both medical and alternative treatment options.

Showing 8 comments
Add your comment

I have extremely bad runny nose. After taking fexofenadine for 6 months, it shows no sign of letting up. Just tilting my head to read my iPad starts a river flowing from my nose. What causes it?

I am a very healthy 52 woman with no medication except vitamins, ambien for sleep and dr, unfortunately told me that I have allergy that to take any otc allergy. decided to take allegra180mg for my 103 lb. body for 2 years and it almost destroyed me.
Changed my personality became agrresive, extreme irritation, anxiety disorder, difficulty breathing, had chronic back pain, bladder problems , hotflashes, dry mouth skin eyes, hair, it ruined me to the point beacme so depressed hated the world… it magnified all my anxiety and really was a healthy woman with no back pain none of the symptoms above.
Thinking it was meonpause and blamed on aging but thank God somehow started researching on this drug and came across a lot of bad reviews from consumers. The Drs do not care at all… they kept prescribing me different pills like xanax to calm me down and zoloft for depression. This is crazy, they knew I was taking allegra and none of them seem to ask me why I am taking it or at least tell me to stop taking it only when symptoms appear…. really I drugged myself to death because they prescribe this otc for my allergy but no specific instruction not for long periods of time.
The FDA should take a look at the labeling of this Allegra and it says take it daily 24 hrs., I am very angry as of now since I just realized 10 days ago that this is the cause cz when I stop this med for two days my upper back pain went away slowly and my body is slowly going back to normal… THE DRS have NO CLUE .

Have used Allegra for at least 20 years. I am allergic to grass and tree pollens. Tried to switch to Claritin when it was released but did not find it as effective so switched back to Allegra, When Fexofenadine was developed, I switched this and found it as effective as Allegra and cheaper. Now both Allegra and Fexofenadine are available over the counter and I am looking for a inexpensive source for either of them!

I have been taking 180mg for months now as the other things the dr had me try first weren’t working. This helps some. I get withdrawal (itching and super-intensified symptoms) for a few days when I stop. When this allergy season is over I think I will go back to raw apple cider vinegar and honey. It’s a tad more inconvenient, but cheaper and safer. I tried trusting the allergist!

I’ve been taking Allegra for about a week, and am having horrible intestinal cramps, the likes of which I’ve never experienced before. When researching it this morning, I discovered that abdominal cramping is a known side effect. I was beginning to worry I had an obstructed bowel or something equally horrible — but now I’m going to take myself off this drug and rely on a neti pot.

I took Allegra for 2 years straight because my allergies were so bad! Now, if I miss 3 days I itch all over and have to take a benedryl to make the intense itching stop. I went to my allergist and found out that I now have urticaria pigmentosa and HAVE to take….(drum roll please)….ALLEGRA!
I never itched a day in my life until I too Allegra for that 2 year period and my body has changed.

I use it all the time, and it works just as well as Allegra since it is the generic for Allegra and made by the same company.

Is Fexofenadine 180 mg tabs as effective as Allegra for

* Be nice, and don't over share. View comment policy^