Allegra vs. Zyrtec vs. Claritin: How Do They Compare?

Allegra (fexofenadine), Zyrtec (cetirizine), and Claritin (loratadine) are over-the-counter (OTC) antihistamines. These allergy pills are used to treat hives, itchy skin, post-nasal drip, and other seasonal allergy symptoms caused by exposure to allergens (such as grass or tree pollen) that trigger an immune response (antibodies) in your body.

When comparing Allegra, Zyrtec, and Claritin, remember that:

• Allegra is less likely to make you drowsy.
• Zyrtec and Allegra work faster than Claritin.
• All three work well to treat hives and symptoms of hay fever.

This article compares Allegra, Claritin, and Zyrtec by looking at how quickly they work, recommended dosages, and side effects. In addition, it details how these medications might be used during pregnancy at the discretion of a healthcare provider.

Allegra vs. Zyrtec vs. Claritin: The Symptoms They Relieve

Allegra, Zyrtec, and Claritin are all over-the-counter antihistamines. Exposure to an allergen such as pet dander, dust mites, or pollen prompts the immune system to release chemicals called histamines.

Antihistamines like Allegra, Zyrtec, and Claritin work by blocking histamines and calming your allergic response.

Zyrtec and Allegra both work quickly for the treatment of allergic rhinitis and hives, typically within less than an hour. You can take Claritin right away when symptoms start, but not more than once or twice per day, depending on the product.

Claritin is a non-drowsy formula and similar to Allegra. Both may be preferable for mild to moderate allergy symptoms since other drugs are more sedating.

For severe symptoms that are interfering with work, school, or play, a medication such as Zyrtec may be needed. It all depends on how much symptom relief you need and the degree of side effects you can tolerate.

Allegra vs. Zyrtec vs. Claritin: Which Makes You Sleepier?

First-generation antihistamines such as Benadryl cross the blood-brain barrier, which can produce a sedative effect. This happens because histamines found in the brain also play a role in keeping you awake. Second-generation antihistamines like Allegra, Zyrtec, and Claritin, don't cross this barrier, so they are less likely to make you feel drowsy.

Claritin and Allegra are non-sedating, meaning unlikely to make you sleepy. Zyrtec, on the other hand, can cause sedation in a minority of people who take it (about one in six). People who are over 60 years old may be more likely to experience sedation.

Allegra and Zyrtec work best when taken at the same time each day, in order to make the most out of symptom relief. Claritin, when used only once a day, also should be taken around the same time.

Drug Forms

Antihistamines are available in several different over-the-counter products. They include:

• Allegra: Gel caps, tablets, dissolve tabs, and syrup
• Claritin: Tablets, chewables, syrup, liquid gels, dissolvables
• Zyrtec: Tablets, chewables, liquid gels, syrup, dissolvables

Some options, including the chewables and syrups, are designed for children. Your pediatrician can help you to decide which products will work best for a child with allergies.

Allegra vs. Zyrtec vs. Claritin Dosage

You should consult your healthcare provider about the best way to take any medication, but there are standard dosing recommendations for all three of these antihistamines.

All of these antihistamines are indicated for adults and children 2 years old and older, with Zyrtec and Claritin dosed once a day for people of all ages.

Allegra is dosed twice a day for children ages 2 to 11 and once a day for adults and children ages 12 and older. Allegra can be used in children as young as 6 months old.

Comparing Side Effects: Allegra vs. Zyrtec vs. Claritin

All three of these drugs can cause mild side effects, including headache, dizziness, stomach pain, and nausea. However, these drugs don't share all of the same potential side effects.

It is possible, though uncommon, to have an allergic reaction to an antihistamine. Seek medical care at once if you experience symptoms like rash or hives, itching or angioedema (swelling of the face, throat, or tongue), or difficulty breathing after taking one of these medications.

Allegra vs. Zyrtec vs. Claritin: Possible Interactions

Not all antihistamines are recommended for all people.

If you're taking Allegra, it's important to avoid drinking fruit juice for one to two hours before you take the medication and one to two hours afterward. Juices such as orange juice or grapefruit juice can decrease the absorption of Allegra by nearly half.

Other considerations when taking second-generation antihistamines include:

• A history of asthma, kidney, or liver disease
• A genetic phenylketonuria (PKU) diagnosis, which makes it important to avoid aspartame often found in dissolving drug tablets
• Whether you take other medications or supplements, especially cold and allergy drugs. People who take Theo-24 (theophylline), sedatives, and mental health medications like antidepressants when taking Zyrtec may need to have their dosages adjusted.
• A history of alcohol or substance use that may increase the risk of adverse effects

Tell your healthcare provider about the use of erythromycin drugs or Nizoral (ketoconazole) when taking Allegra, and be sure to use any antacids a few hours before or after your medication.

Summary

Claritin, Zyrtec, and Allegra are all good antihistamine options and are generally well-tolerated by many people. But some differences between them may make one of these antihistamines better for you than the others.

For example, Zyrtec and Allegra may work faster than Claritin. Zyrtec and Claritin can make you sleepy, while Allegra usually won't. If you're unsure of which antihistamine to select, consult your healthcare provider or pharmacist.