Allegra (fexofenadine) is an antihistamine that reduces the natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Allegra is used to treat the symptoms of seasonal allergies (hay fever) in adults and children. Allegra is also used to treat skin itching and hives caused by a condition called chronic idiopathic urticaria in adults and children.

The health and medical information provided here is for general purposes only and is not a substitute for the expertise and judgment of your physician, or other health care professional. It should not be understood to indicate that the use of this medicine is safe, appropriate or effective for you. Always consult your health care professional before using this, or any other, drug.

Before using Allegra, tell your doctor if you are allergic to any drugs, or if you have kidney disease.
Fruit juices and certain antacids can make it harder for your body to absorb Allegra. Take the disintegrating tablet on an empty stomach, at least 1 hour before or 2 hours after a meal.
There may be other drugs that can affect Allegra. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.
Stop using this medication and get emergency medical help if you think you have used too much medicine, or if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Tell your doctor if your symptoms do not improve, or if they get worse after you start taking Allegra. Never take more of the medication than your doctor has prescribed

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop taking Allegra and call your doctor if you have fever, chills, body aches, cough, or other flu symptoms.
Less serious Allegra side effects may include:
nausea, diarrhea, upset stomach;
menstrual cramps;
drowsiness, tired feeling;
headache; or
muscle or back pain.

Take Allegra exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.
Take the regular Allegra tablets with a full glass of water. Do not use any other type of liquid. Shake the oral suspension (liquid) well just before you measure a dose. To be sure you get the correct dose, measure the liquid with a marked measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.
To take fexofenadine orally disintegrating tablets (Allegra ODT):
Keep the tablet in its blister pack until you are ready to take the medicine. Open the package and peel back the foil from the tablet blister. Do not push a tablet through the foil or you may damage the tablet.
Using dry hands, remove the tablet and place it in your mouth. It will begin to dissolve right away.
Do not swallow the tablet whole. Allow it to dissolve in your mouth without chewing.
Swallow several times as the tablet dissolves. If desired, you may drink liquid to help swallow the dissolved tablet.
Take the disintegrating tablet on an empty stomach, at least 1 hour before or 2 hours after a meal.
Tell your doctor if your symptoms do not improve, or if they get worse after you start taking Allegra. Never take more of the medication than your doctor has prescribed.
Store Allegra at room temperature away from moisture and heat. Keep the medicine bottle tightly closed.