Allegra and Claritin are allergy medications that help relieve symptoms such as sneezing, a runny nose, and itchy eyes. The active ingredients are different. Allegra contains fexofenadine, and Claritin has loratadine.

Allegra (fexofenadine)and Claritin (loratadine) are over-the-counter (OTC) medications that can help relieve allergy symptoms. They’re both antihistamines, which work by blocking histamine from binding to H1 receptors.

While these drugs work in a similar way, they’re not identical. Read on to learn about some of the main differences between Allegra and Claritin.

Some of the key features of Allergra and Claritin are the symptoms they treat, their active ingredients, and the forms they come in.

  • Symptoms they treat: Both Allegra and Claritin can treat the following symptoms:
    • sneezing
    • runny nose
    • itchy, watery eyes
    • itchy nose and throat
  • Active ingredients: The active ingredient in Allegra is fexofenadine. The active ingredient in Claritin is loratadine.
  • Forms: Both drugs come in a variety of OTC forms. These include an orally disintegrating tablet, oral tablet, and oral capsule.

Claritin also comes in chewable tablets and oral solutions, while Allegra comes as an oral suspension. However, these forms are approved to treat different ages. If the medication is for a child, this could be an important distinction in making your choice.

Don’t give either drug to children who are younger than the suitable age. For example, chewable Claritin is generally suitable for children from the age of 2 years, while the Allegra tablet is suitable from the age of 12 years.

For specific dosage information for adults or children, read the product package carefully or talk with a doctor or pharmacist.

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Allegra and Claritin are newer, or second-generation, antihistamines. One benefit of using newer antihistamines is that they cause fewer side effects than older antihistamines.

The other side effects of Allegra and Claritin are similar, but in most cases, people don’t experience any side effects with either drug. That said, the following tables list examples of possible side effects of these drugs.

Common side effectsAllegraClaritin
Nausea✓
Tiredness✓✓
Headaches✓✓
Dizziness✓
Nervousness✓

Serious side effects with Allegra or Claritin are rare. However, some people mahy experience anaphylaxis, a serious allergic reaction.

If anaphylaxis occurs, seek immediate medical help.

Anaphylaxis

Anaphylaxis is a severe reaction to a trigger, such as an allergy, and is potentially life threatening.

Symptoms can develop quickly and include:

  • feeling faint or lightheaded
  • difficulty breathing or wheezing
  • rapid heartbeat
  • confusion
  • anxiety
  • clammy skin
  • collapsing or losing consciousness
  • hives
  • swelling
  • stomach pain, nausea, or vomiting

If you or someone nearby develops these symptoms, you should:

  1. Check to see whether they have an epinephrine pen. If they do, read and follow the instructions to dispense the medication.
  2. Dial 911 (or a local emergency number).
  3. Lay them down. If they have vomited, lay them on their side.
  4. Stay with them until emergency services arrive.

It is possible for someone to need more than one injection with an epinephrine pen. If symptoms do not begin to clear after 5 minutes, give a second injection if one is available.

Two things you should consider when taking any medication are the possible drug interactions and potential problems related to any existing health conditions. These are not all the same for Allegra and Claritin.

Drug interactions

A drug interaction occurs when a medication changes the way another drug works. This can be harmful or prevent the drug from working well.

Allegra and Claritin interact with some of the same drugs. Specifically, each may interact with ketoconazole and erythromycin. Claritin can also interact with cimetidine and clarithromycin.

To help avoid interactions, be sure to tell your doctor about all prescription and OTC drugs, herbs, and supplements you take. They can tell you about what interactions you might be at risk of in using Allegra or Claritin.

Health conditions

Some drugs aren’t a good choice if you have certain health conditions.

For example, both Allegra and Claritin can cause problems if you have kidney disease. And certain forms may be dangerous if you have a condition called phenylketonuria.

If you have either of these conditions, talk with your doctor before taking Allegra or Claritin. You should also talk with your doctor about the safety of Claritin if you have liver disease.

Both Allegra (fexofenadine)and Claritin (loratadine) can help treat symptoms of allergies. In general, they’re tolerated well by most people.

The main differences between these two medications include their active ingredients, forms, and possible drug interactions.

Before taking either medication, talk with a doctor or pharmacist. You can work with them to choose the one that’s best for you.