Allegra

Chronic Urticaria, Hay Fever, antihistamine
Treatment
2 FDA approvals
1 Active Study for Allegra

What is Allegra

FexofenadineThe Generic name of this drug
Treatment SummaryFexofenadine is an antihistamine medication available without a prescription to treat allergies. It is more selective than first-generation antihistamines, like diphenhydramine, and does not cause sedation or cross the blood-brain barrier, reducing side effects. Fexofenadine is the active metabolite of terfenadine and is sold as a racemic mixture, meaning that it contains equal amounts of two different enantiomers with similar antihistamine activity.
Allegra D-12 Houris the brand name
image of different drug pills on a surface
Allegra Overview & Background
Brand Name
Generic Name
First FDA Approval
How many FDA approvals?
Allegra D-12 Hour
Fexofenadine
1997
525

Approved as Treatment by the FDA

Fexofenadine, also known as Allegra D-12 Hour, is approved by the FDA for 2 uses including Hay Fever and Chronic Urticaria .
Hay Fever
Chronic Urticaria

Effectiveness

How Allegra Affects PatientsFexofenadine is an allergy medication that works by blocking the action of histamine, which is the chemical that causes allergy symptoms. It produces effects quickly, usually within 1-3 hours, and its effects can last up to 24 hours with once or twice daily dosing. Fexofenadine should not be taken with fruit juice, as this may stop it from working properly.
How Allegra works in the bodyFexofenadine is used to treat allergic reactions. It works by blocking the H1 histamine receptor, which is responsible for the body's allergic response. When this receptor is blocked, it prevents the release of pro-inflammatory molecules like interleukins, which are responsible for the symptoms of an allergic reaction. Fexofenadine is a powerful and specific blocker of the H1 receptor, and does not cross the blood-brain barrier, meaning that it won't cause unwanted side effects in the brain.

When to interrupt dosage

The measure of Allegra depends upon the determined condition, including Hay Fever, Hay Fever and antihistamine. The extent of dosage fluctuates, as per the method of administration specified in the table beneath.
Condition
Dosage
Administration
Chronic Urticaria
, 60.0 mg, 180.0 mg, 6.0 mg/mL, 30.0 mg/mL, 30.0 mg, 120.0 mg
, Oral, Tablet, extended release, Tablet, extended release - Oral, Tablet, film coated, Tablet, film coated - Oral, Suspension, Suspension - Oral, Tablet, Tablet - Oral, Tablet, film coated, extended release, Tablet, film coated, extended release - Oral, Tablet, coated, Tablet, coated - Oral, Tablet, orally disintegrating, Tablet, orally disintegrating - Oral, Capsule, Capsule - Oral, Tablet, multilayer, extended release, Tablet, multilayer, extended release - Oral, Capsule, coated, Capsule, coated - Oral
Hay Fever
, 60.0 mg, 180.0 mg, 6.0 mg/mL, 30.0 mg/mL, 30.0 mg, 120.0 mg
, Oral, Tablet, extended release, Tablet, extended release - Oral, Tablet, film coated, Tablet, film coated - Oral, Suspension, Suspension - Oral, Tablet, Tablet - Oral, Tablet, film coated, extended release, Tablet, film coated, extended release - Oral, Tablet, coated, Tablet, coated - Oral, Tablet, orally disintegrating, Tablet, orally disintegrating - Oral, Capsule, Capsule - Oral, Tablet, multilayer, extended release, Tablet, multilayer, extended release - Oral, Capsule, coated, Capsule, coated - Oral
antihistamine
, 60.0 mg, 180.0 mg, 6.0 mg/mL, 30.0 mg/mL, 30.0 mg, 120.0 mg
, Oral, Tablet, extended release, Tablet, extended release - Oral, Tablet, film coated, Tablet, film coated - Oral, Suspension, Suspension - Oral, Tablet, Tablet - Oral, Tablet, film coated, extended release, Tablet, film coated, extended release - Oral, Tablet, coated, Tablet, coated - Oral, Tablet, orally disintegrating, Tablet, orally disintegrating - Oral, Capsule, Capsule - Oral, Tablet, multilayer, extended release, Tablet, multilayer, extended release - Oral, Capsule, coated, Capsule, coated - Oral

Warnings

Allegra Contraindications
Condition
Risk Level
Notes
Severe Hypersensitivity Reactions
Do Not Combine
Fexofenadine may interact with Pulse Frequency
There are 20 known major drug interactions with Allegra.
Common Allegra Drug Interactions
Drug Name
Risk Level
Description
Pitolisant
Major
The therapeutic efficacy of Pitolisant can be decreased when used in combination with Fexofenadine.
Abemaciclib
Moderate
The serum concentration of Abemaciclib can be increased when it is combined with Fexofenadine.
Ambrisentan
Moderate
The serum concentration of Ambrisentan can be increased when it is combined with Fexofenadine.
Apixaban
Moderate
The serum concentration of Apixaban can be increased when it is combined with Fexofenadine.
Avanafil
Moderate
The serum concentration of Avanafil can be increased when it is combined with Fexofenadine.
Allegra Toxicity & Overdose RiskIn mice and rats, no deaths occurred after taking up to 5000 mg/kg of Fexofenadine orally, which is around 100-200 times the recommended human dose. People who have taken up to 800 mg in one dose or 690 mg twice daily for a month have not shown any severe side effects. Symptoms of overdosing on Fexofenadine may include dizziness, drowsiness, and dry mouth. If an overdose occurs, treatment should be focused on mitigating symptoms. Dialysis does not effectively remove Fexofenadine from the blood.
image of a doctor in a lab doing drug, clinical research

Allegra Novel Uses: Which Conditions Have a Clinical Trial Featuring Allegra?

Currently, 7 active studies are analyzing the effectiveness of Allegra in providing antihistamine, Chronic Idiopathic Urticaria and Hay Fever relief.
Condition
Clinical Trials
Trial Phases
Hay Fever
0 Actively Recruiting
Chronic Urticaria
1 Actively Recruiting
Phase 4
antihistamine
0 Actively Recruiting

Allegra Reviews: What are patients saying about Allegra?

4.7Patient Review
12/21/2018
Allegra for Hives
This worked great for my hives! The only thing is that I noticed my blood pressure seemed to rise. Has anyone else experienced this side effect?
3.7Patient Review
5/30/2016
Allegra for Inflammation of the Nose due to an Allergy
I took this medication for a long time with no problems, but recently developed severe cramps in my extremities. Once I stopped taking the Allegra, the cramps went away; upon restarting it, they came back again. So, unfortunately, I think I'll have to give up on this medication.
3.3Patient Review
9/16/2020
Allegra for Inflammation of the Nose due to an Allergy
This medication does a great job at alleviating my allergies, but unfortunately it also gives me pretty bad stomach pain.
2.7Patient Review
4/15/2015
Allegra for Persistent Hives of Unknown Cause
I had an allergic reaction to the Costco brand of this drug; my skin broke out in a rash all over my arms. I'm glad my reaction was not as severe as one of the reviewers.
2.3Patient Review
8/8/2016
Allegra for Inflammation of the Nose due to an Allergy
Unfortunately, I developed an allergic reaction to the allegra. My throat started swelling up as well as my face. It was scary. So be careful- you might develop allergies to antihistamines even if you've never had them before.
2.3Patient Review
10/6/2014
Allegra for Hives
I tried the generic/otc version of Allegra and experienced a number of issues that I see others reporting. In addition to the Allegra, I took medication in the middle of the day to help with sleep. However, I still had difficulty sleeping. Additionally, my skin became more itchy and I developed cramps in my feet.
2Patient Review
4/24/2018
Allegra for Hives
Unfortunately, this medication did not work for me at all. Not only that, but I also experienced some adverse side effects, including chest tightness and a fever.
2Patient Review
8/22/2017
Allegra for Runny Nose
Completely ineffective. I want a refund.
2Patient Review
5/30/2014
Allegra for Inflammation of the Nose due to an Allergy
This treatment does offer some relief, but it is limited in its effectiveness.
1Patient Review
3/1/2020
Allegra for Allergic Conjunctivitis
I was directed by my medical pulmonary specialist to take this medication, which I did for an entire winter. However, I started gaining weight and felt generally worse while taking it. Once I stopped taking the medication, I started losing weight again.
1Patient Review
4/24/2016
Allegra for Seasonal Runny Nose
I followed the instructions for this medication and saw no more than an hour of relief from my symptoms.
1Patient Review
5/3/2022
Allegra for Seasonal Runny Nose
Unfortunately, Allegra did not help alleviate any of my allergy symptoms. If anything, it made them worse.
image of drug pills surrounding a glass of water symbolizing drug consumption

Patient Q&A Section about allegra

These questions and answers are submitted by anonymous patients, and have not been verified by our internal team.

What is Allegra best used for?

"Fexofenadine works by blocking histamines that are produced by the body. This helps to reduce the symptoms of hay fever and otherupper respiratory allergies."

Answered by AI

Are Allegra and Zyrtec the same?

"The main idea is that Allegra and Zyrtec are both safe and effective drugs to treat allergy symptoms, but Zyrtec's effects may last longer. Zyrtec may also cause drowsiness, while Allegra may be less effective if you drink fruit juices."

Answered by AI

Are Claritin and Allegra the same?

"Both Allegra and Claritin are antihistamines, but they have different active ingredients. Allegra has fexofenadine hydrochloride and Claritin has loratadine."

Answered by AI

Do Benadryl and Allegra do the same thing?

"Benadryl can be used to help with insomnia, motion sickness, and mild cases of Parkinson's disease. Benadryl generally causes more drowsiness and sedation than Allegra. Both Benadryl and Allegra are available in generic form and can be bought without a prescription."

Answered by AI

Clinical Trials for Allegra