Children's Allegra Side Effects and Dosing

Allegra (fexofenadine) is an over-the-counter antihistamine used to treat allergies in children and adults. Children's Allegra is approved to treat seasonal allergic rhinitis (hay fever) in children over the age of 2 and chronic idiopathic urticaria (hives) in children over age 6 months.

Boy sneezing in classroom
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Allegra offers a line of many different allergy medications; two are formulated specifically for children:

  • Children's Allegra Oral Suspension: This liquid form of Allegra provides long-lasting allergy relief and it's non-drowsy. It's safe to treat seasonal allergies in children ages 2 and up, and hives in children over 6 months. It provides 12 hours of relief. A liquid medication is helpful for children who can't yet swallow pills.
  • Children's Allegra Meltable Tablets: Melt-in-your-mouth tablets are perfect for kids who don't like liquid medicine or can't swallow pills. These tablets provide 12 hours of relief, are non-drowsy, and are safe for kids ages 6 and up.

Because Children's Allegra provides 12 hours of relief, most kids take it twice a day. Before you administer Allegra to your child, know that it can interact with other substances, including:

  • Erythromycin
  • Ketoconazole
  • Magnesium
  • Antacids such as Maalox
  • Certain fruit juices

Taking Allegra with these other medications can increase the risk of side effects. As well, fruit juice (even in low-concentration drinks) will decrease the absorption of Allegra and reduce its effectiveness.

Dosing Instructions

Children 6 to 23 months with chronic idiopathic urticaria are usually given 1/2 teaspoon twice a day, increasing to 1 teaspoon twice a day for children between the ages of 2 and 11 years of age. Children 2 to 11 years are usually given 1 teaspoon twice a day for seasonal allergic rhinitis.

Older children between the ages of 6 and 11 years of age who can swallow a pill can take a 30 milligram Allegra tablet twice a day instead of the Allegra liquid medication. Adults and children, 12 years and older can take a 60 milligram Allegra tablet twice a day or 180 milligrams once a day for chronic idiopathic urticaria or seasonal allergic rhinitis.

Allegra tablets should be taken with water and not fruit juice (such as grapefruit, orange, or apple juice). Fruit juices should be avoided one to two hours both before and after a dose of Allegra.

Side Effects

Allegra users rarely experience side effects and, if they do, they are usually pretty mild. Still, if your child takes Allegra and is experiencing any of the symptoms listed below, you should call your doctor immediately. Known side effects of Allegra include:

  • Drowsiness
  • Headaches
  • Vomiting
  • Fever
  • Muscle or back pain
  • Coughing
  • Ear infection
  • Runny noses
  • Nausea
  • Diarrhea
  • Upper respiratory infection

What to Do If Allegra Doesn't Work

If Allegra does not work for your child, try one of the many alternative allergy medications, including Claritin, Clarinex, Zyrtec, or Singulair. If your child is old enough, your doctor may also prescribe a steroid nasal spray such as Flonase, Nasonex or Rhinocort Aqua.

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Article Sources
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  1. Allegra Allergy. Children’s allegra liquid.

  2. Allegra Allergy. Children’s Allegra Meltable Tablets.

  3. Allegra. Highlights of prescribing information. Revised July 2007.

Additional Reading
  • Phan, H; Moeller, Nahata (2009). "Treatment of Allergic Rhinitis in Infants and Children: Efficacy and Safety of Second-Generation Antihistamines and the Leukotriene Receptor Antagonist Montelukast."