What It Is

Fexofenadine is a second-generation antihistamine used primarily to relieve symptoms of allergic conditions such as seasonal allergic rhinitis and chronic idiopathic urticaria. Unlike first-generation antihistamines, fexofenadine is less likely to cause sedation, making it a preferred choice for individuals who need to avoid drowsiness.

Dosage Forms and Strengths

Fexofenadine is available in several dosage forms and strengths:

• Tablets: 30 mg, 60 mg, and 180 mg
• Oral Suspension: 30 mg/5 mL

The dosage form and strength are selected based on the patient’s age, the severity of symptoms, and the specific condition being treated.

Brand and Generic Names

The most commonly known brand name for fexofenadine is Allegra. It is also available in various generic forms under the name "Fexofenadine."

Indications for Use

Fexofenadine is primarily indicated for:

• Seasonal Allergic Rhinitis: It alleviates symptoms such as sneezing, runny or itchy nose, and itchy or watery eyes caused by hay fever.
• Chronic Idiopathic Urticaria: It helps to reduce the symptoms of chronic hives, including itching and rash.

Mechanism of Action

Fexofenadine works as a selective antagonist of peripheral H1 histamine receptors. By blocking these receptors, it prevents the action of histamine, a substance in the body that causes allergic symptoms such as itching, swelling, and mucus production. Unlike some other antihistamines, fexofenadine does not readily cross the blood-brain barrier, which contributes to its reduced sedative effects.

Administration and Dosage

Fexofenadine is administered orally. The typical dosing recommendations are:

• Adults and Children ≥12 Years: For allergic rhinitis, the usual dose is 60 mg twice daily or 180 mg once daily. For chronic idiopathic urticaria, the recommended dose is 60 mg twice daily.
• Children 6-11 Years: The recommended dose for allergic rhinitis is 30 mg twice daily or 60 mg once daily. For chronic idiopathic urticaria, the dose is 30 mg twice daily.

The oral suspension is generally used for children who have difficulty swallowing tablets.

Side Effects and Precautions

Common side effects of fexofenadine may include:

• Headache
• Drowsiness (though less common than with first-generation antihistamines)
• Dry mouth
• Nausea

Severe side effects are rare but can include allergic reactions like rash, itching, or swelling. If any severe symptoms occur, medical attention should be sought immediately.

Precautions:

• Pregnancy and Lactation: Fexofenadine should be used during pregnancy only if clearly needed and prescribed by a healthcare provider. It is excreted in breast milk, so caution is advised for breastfeeding mothers.
• Kidney Function: Dose adjustments may be necessary for patients with impaired kidney function.
• Interactions: Fexofenadine should be used cautiously with certain medications, such as antacids containing aluminum or magnesium, as they may reduce its absorption.

Conclusion

Fexofenadine is an effective second-generation antihistamine for managing symptoms of allergic rhinitis and chronic urticaria. Its reduced sedative effects compared to first-generation antihistamines make it a suitable option for those who need to avoid drowsiness. As with any medication, proper administration and adherence to dosage recommendations are crucial for optimal efficacy and safety. Patients should consult their healthcare provider for personalized advice, especially regarding potential interactions and precautions.