Fexofenadine: Uses, Dosage, Side Effects & Precautions

What Is Fexofenadine?

Fexofenadine is a second-generation antihistamine used to treat allergic conditions such as hay fever, allergic rhinitis and chronic hives (urticaria). It helps relieve symptoms like sneezing, runny nose, itchy eyes and itchy skin, and it is less likely to cause drowsiness than older antihistamines.

At a Glance

How Fexofenadine Works

Fexofenadine blocks histamine, a chemical released during allergic reactions, which helps ease swelling, itching and redness. It has relatively little penetration into the brain, which is why it is less likely to cause sleepiness.

When to Use Fexofenadine

• Hay fever and allergic rhinitis: Relieves sneezing, runny nose, and itchy or watery eyes, including when triggered by seasonal allergens such as pollen.

• Chronic hives (urticaria): Helps reduce hives and itching in chronic urticaria with no identified cause.

Sudden swelling of the face, lips, tongue or throat, or difficulty breathing, is a medical emergency. Get urgent medical help immediately and do not rely on fexofenadine alone.

Dosage

Dosing depends on the condition, age, product form and kidney function. The doses below follow Indian prescribing information for Allegra. They should be prescribed or confirmed by a doctor.

Adults and children 12 years and above

• Allergic rhinitis: 120 mg once daily or 180 mg once daily.

• Chronic hives: 180 mg once daily.

Children (oral suspension)

• Allergic rhinitis, 2–11 years: 30 mg twice daily.

• Chronic hives, 2–11 years: 30 mg twice daily.

• Chronic hives, 6 months to under 2 years: 15 mg twice daily.

Kidney problems

For allergic rhinitis, a lower starting dose is recommended in decreased kidney function. This is 60 mg once daily in adults and adolescents 12 and above, and 30 mg once daily in children 2–11. Dosing for other indications and ages in kidney impairment should be decided by a doctor.

Studies in older adults and in people with liver impairment indicate that the dose does not need adjusting on the basis of age or liver function alone. Kidney function and other medicines still matter, so tell your doctor about both.

Labels in other countries may list different regimens, such as 60 mg twice daily. This is not the Indian recommendation, so follow your product’s label and your doctor’s advice.

Do not give fexofenadine to a child, or change a dose, without medical advice. Do not exceed the prescribed dose.

How to Take It

Take the tablet with water. Do not take it with apple, orange or grapefruit juice, which can reduce how much medicine your body absorbs.

Side Effects

Most frequent: Headache is the most frequently reported side effect. Drowsiness, dizziness and nausea are reported less often.

Seek urgent medical help for: Signs of a serious allergic reaction, such as rash with swelling of the face, lips, tongue or throat, or difficulty breathing.

If you feel drowsy or dizzy, avoid driving or operating machinery. Alcohol may add to drowsiness.

Precautions

Do not use it if you are allergic to fexofenadine or any ingredient in the product. Tell your doctor if you have kidney problems, as the dose may need to be adjusted. Older adults should have their kidney function and other medicines considered.

Drug and Food Interactions

• Fruit juices (apple, orange, grapefruit): These can reduce absorption of fexofenadine. Take it with water.

• Antacids containing aluminium or magnesium: Take fexofenadine 2 hours before or after these antacids.

• Erythromycin or ketoconazole: These medicines can raise fexofenadine levels, but studies did not show significant QTc changes with these combinations. Tell your doctor or pharmacist if you take them.

• P-gp inducers (such as apalutamide): These may lower fexofenadine exposure.

Tell your doctor or pharmacist about all medicines and supplements you use. This is not a complete list.

Pregnancy and Breastfeeding

Human data on fexofenadine in pregnancy are limited. Studies so far have not found an increased chance of birth defects or miscarriage, but this does not mean it is risk-free. Indian prescribing information advises use only if the potential benefit outweighs the potential risk, so the decision should be made with a healthcare professional.

Fexofenadine passes into breast milk in small amounts, and use by a breastfeeding mother is not expected to cause side effects in the baby. Data are limited, so discuss it with your doctor. Combination products that also contain a decongestant can reduce milk supply.

Brands and Strength

Common brands in India include Allegra and Fexo. Allegra is available as 120 mg and 180 mg tablets and as an oral suspension (30 mg per 5 mL) for children. Fexo is available as 120 mg tablets. Strength and form vary by brand and product, so check the label.

Brands, Strength and Approximate Price in India

How HealthPil Can Help

Medicines should be started, changed or stopped only under the guidance of a qualified healthcare professional. If you have ongoing allergy symptoms, recurring hives, or questions about your treatment, you can consult a doctor through HealthPil.