What is loratadine used for?: A comprehensive guide

October 6, 2025 •

3 min read

An estimated 50 million Americans suffer from allergies annually, and many turn to over-the-counter medication for relief. A popular choice for managing symptoms is loratadine, a second-generation antihistamine used for effectively treating allergy-related conditions.

Quick Summary

Loratadine is a second-generation antihistamine providing 24-hour relief from symptoms of seasonal and perennial allergies, and chronic hives. It works by blocking histamine and is known for being less sedating than older antihistamines.

Key Points

Second-Generation Antihistamine: Loratadine is a non-drowsy medication that effectively blocks the action of histamine, the chemical responsible for allergic symptoms, with minimal sedation.
Relieves Allergy Symptoms: The primary use for loratadine is to relieve symptoms of seasonal (hay fever) and perennial allergies, including sneezing, runny nose, and itchy, watery eyes.
Treats Hives: Loratadine is also indicated for the treatment of itching and redness caused by chronic idiopathic urticaria (hives).
Long-Lasting Relief: A single daily administration of loratadine can provide 24 hours of relief from allergy symptoms, offering sustained effectiveness.
Multiple Formulations: The medication is available in various forms, including tablets, chewables, and liquid, to suit different user needs and ages.
Generally Well-Tolerated: Most side effects, such as headache and mild drowsiness, are infrequent and mild, making it a suitable option for daily use.
Consult a Professional for Combination Products: While plain loratadine is generally safe during pregnancy, combination products with decongestants (e.g., pseudoephedrine) should be avoided, and professional medical advice is recommended.

Understanding Loratadine: The Non-Drowsy Antihistamine

Loratadine, widely known by its brand name Claritin, is an over-the-counter (OTC) medication classified as a second-generation antihistamine. Unlike older, first-generation antihistamines such as diphenhydramine (Benadryl), loratadine is less likely to cause drowsiness. This is because it is selective for peripheral H1 receptors and does not effectively cross the blood-brain barrier.

When the body encounters an allergen, it releases a chemical called histamine, which is responsible for triggering common allergy symptoms. Loratadine works by blocking the action of this histamine, providing relief from the associated symptoms. Its effects typically last for 24 hours, making a once-daily administration effective for sustained symptom management.

Primary Uses for Loratadine

Loratadine is primarily used to treat various allergic conditions. Its effectiveness and long-lasting action make it a go-to medication for many individuals seeking symptom relief.

Seasonal Allergic Rhinitis (Hay Fever): This is one of the most common uses for loratadine. It is effective at temporarily relieving a runny nose, sneezing, and the redness, itching, and tearing of the eyes caused by seasonal allergies.
Perennial Allergic Rhinitis: For those with year-round allergies triggered by indoor allergens like dust mites or pet dander, loratadine provides consistent symptomatic relief.
Chronic Idiopathic Urticaria (Hives): The medication is also used to treat the itching and redness associated with hives. Some patients with chronic urticaria may benefit from specific prescribed uses under the supervision of a clinician.

How to Take Loratadine: Formulations

Loratadine is available in several formulations. It is crucial to follow the directions on the package label or consult a healthcare provider, especially for children.

Available Forms:

Tablets: Available in various strengths.
Chewable Tablets: Often available in different strengths for children.
Oral Solution/Syrup: A liquid form is available for children, with administration based on age.
Rapidly Disintegrating Tablets (RediTabs): Designed to dissolve quickly on the tongue for those who have trouble swallowing pills.

It is also available in combination products (e.g., Claritin-D), which include a decongestant like pseudoephedrine to treat nasal stuffiness.

Common Side Effects and Precautions

While generally well-tolerated, loratadine can cause some side effects. Most are mild, but it is important to be aware of potential reactions and precautions.

Common Side Effects:

Headache
Mild drowsiness or fatigue
Dry mouth
Nervousness
Gastrointestinal upset (e.g., nausea, abdominal pain)

Precautions and Warnings:

Hepatic or Renal Impairment: Patients with liver or kidney disease may require specific considerations from a healthcare provider.
Pregnancy and Breastfeeding: While considered generally safe, it is always recommended to consult a doctor before use, and avoid combination products containing pseudoephedrine.
Children under 2: Use is not recommended without a doctor's consultation.
Serious Side Effects: Stop taking loratadine and seek medical help if you experience a rash, hives, swelling of the face, lips, or tongue, or difficulty breathing.

Loratadine vs. Other Antihistamines: A Comparison

Choosing between different antihistamines often depends on individual response, desired onset of action, and potential side effects. Here is a comparison of loratadine with two other common antihistamines:


Feature	Loratadine (Claritin)	Cetirizine (Zyrtec)	Diphenhydramine (Benadryl)
Generation	Second-generation	Second-generation	First-generation
Drowsiness Risk	Low/Non-drowsy	Moderate; higher than loratadine	High; significant sedation
Onset of Action	1–3 hours	20–60 minutes; faster than loratadine	15–60 minutes; fast
Duration of Action	24 hours	24 hours	4–6 hours
Primary Uses	Seasonal/perennial allergies, hives	Seasonal/perennial allergies, hives	Seasonal/perennial allergies, sleep aid, cold symptoms
Unique Notes	Long-acting, well-tolerated.	Faster onset; potential for withdrawal itching.	Can be used as a sleep aid; not ideal for daytime use due to sedation.

Conclusion: Choosing the Right Allergy Relief

Loratadine is a widely available and effective medication for treating a variety of allergic symptoms, particularly seasonal and perennial allergies and chronic hives. As a second-generation antihistamine, it offers the benefit of 24-hour relief with a lower risk of drowsiness compared to older alternatives. While it is generally well-tolerated, it is important to follow administration instructions and be aware of potential side effects and interactions. For sustained, non-drowsy relief from allergic rhinitis, loratadine remains a highly recommended option for many individuals. However, consulting a healthcare professional is advisable to determine if it is the best choice for your specific needs, especially if you have other health conditions or are taking other medications.

For more detailed prescribing information and clinical studies, refer to MedCentral's professional monograph on Loratadine.

Frequently Asked Questions

Yes, loratadine is suitable for children over the age of two, though the appropriate usage and formulation depend on the child's age. It is best to consult with a doctor before giving it to children.

Loratadine typically begins to work within 1 to 3 hours after being taken. Its peak effects are usually felt within 8 to 12 hours.

Loratadine is available in combination products with decongestants like pseudoephedrine (e.g., Claritin-D), which can help with nasal congestion. However, you should not take multiple oral antihistamines at once, and some individuals, like pregnant women, should avoid the decongestant component.

Loratadine can be very effective for managing the symptoms of allergic rhinitis and hives. However, for severe or life-threatening allergic reactions, such as anaphylaxis, it is not an appropriate treatment. In those cases, immediate medical attention is necessary.

Loratadine is considered a non-drowsy antihistamine because it does not cross the blood-brain barrier as readily as first-generation antihistamines. While drowsiness is a potential side effect, it is uncommon and generally mild when it occurs.

Both are second-generation antihistamines, but there are some differences. Cetirizine (Zyrtec) may act faster but also has a higher potential to cause drowsiness compared to loratadine. Some people may also experience itching when stopping cetirizine.

Yes, it is safe to take loratadine every day for as long as your symptoms persist, provided you are following appropriate administration guidelines. Long-term use in clinical studies has not shown tolerance issues.

Loratadine is primarily an antihistamine used for allergy symptoms and hives. It is not typically used or recommended for the prevention or treatment of motion sickness, as other antihistamines (like first-generation ones) are generally more effective for this purpose.