Allegra (fexofenadine hydrochloride) is a leading second-generation antihistamine specifically formulated to provide powerful, 24-hour relief from seasonal and perennial allergy symptoms without causing sedation. As a prescription-to-OTC transition medication, it represents a significant advancement in allergy management, offering efficacy comparable to older agents but with a markedly improved safety and tolerability profile. Its rapid onset of action and sustained effect make it a first-line recommendation for patients seeking to maintain normal daily function while controlling allergic responses. This expert review covers its pharmacological profile, appropriate use, and clinical considerations.

Features

• Active ingredient: Fexofenadine hydrochloride 60 mg or 180 mg (tablets); 30 mg/5 mL (oral suspension)
• Drug class: Second-generation (non-sedating) H1-receptor antagonist
• Duration of action: Up to 24 hours per dose
• Formulations: Oral tablets, orally disintegrating tablets, and liquid suspension
• Prescription status: Over-the-counter (OTC) for ages 6+; prescription forms available for younger pediatric populations
• Onset of action: Symptom relief typically begins within 1 hour

Benefits

• Provides rapid and continuous relief from sneezing, runny nose, itchy/watery eyes, and itchy throat/palate
• Non-drowsy formula allows unimpaired alertness, concentration, and motor function—ideal for work, school, or driving
• 24-hour duration enables once-daily dosing for consistent symptom control
• Suitable for both seasonal allergic rhinitis (hay fever) and chronic idiopathic urticaria (hives)
• No known cardiotoxicity at recommended doses, unlike some first-generation antihistamines
• Minimal drug interactions due to low metabolism by cytochrome P450 enzymes

Common use

Allegra is indicated for the relief of symptoms associated with seasonal allergic rhinitis in adults and children 6 years of age and older. These symptoms include sneezing, rhinorrhea, pruritus of the nose/palate/throat, and ocular itching/redness/tearing. It is also approved for the treatment of uncomplicated skin manifestations of chronic idiopathic urticaria—reducing pruritus and decreasing the number and size of hives. Many clinicians also consider it appropriate for mild allergic reactions, though not for acute anaphylaxis.

Dosage and direction

For adults and children 12 years and older: 60 mg twice daily or 180 mg once daily. For children 6 to 11 years: 30 mg twice daily. Should be taken with water on an empty stomach; avoid concomitant intake of fruit juices (e.g., apple, orange, grapefruit), which can significantly reduce absorption. Dosage adjustment is recommended in patients with renal impairment. Do not crush, chew, or break tablets; orally disintegrating tablets should be placed on the tongue and allowed to dissolve before swallowing.

Precautions

Use with caution in patients with renal impairment; dosage reduction is advised. Although fexofenadine is not sedating, individual responses may vary—observe response before engaging in activities requiring full alertness. Not recommended during pregnancy unless clearly needed (Category C). Elderly patients may be more susceptible to adverse effects, particularly if renal function is compromised. Keep out of reach of children.

Contraindications

Hypersensitivity to fexofenadine hydrochloride or any component of the formulation. Not intended for use in children under 6 years of age unless under specific medical supervision. Do not use in patients with severe renal impairment (CrCl < 30 mL/min) without medical guidance.

Possible side effect

Most side effects are mild and comparable to placebo. Reported adverse reactions include headache (~1.3%), drowsiness (uncommon, ~1.1%), nausea (~1.5%), dyspepsia, and dizziness. Back pain, sinusitis, and viral infection have also been reported but are not necessarily drug-related. Severe reactions such as tachycardia, hypersensitivity, or anaphylaxis are extremely rare.

Drug interaction

Fexofenadine is a substrate of P-glycoprotein; concomitant use with ketoconazole or erythromycin may increase fexofenadine plasma levels. Antacids containing aluminum or magnesium can reduce absorption and should be taken at least 2 hours apart. Avoid taking with fruit juices, which can decrease bioavailability by inhibiting OATP transporters.

Missed dose

If a dose is missed, take it as soon as remembered. If it is near the time of the next dose, skip the missed dose and resume the regular dosing schedule. Do not double the dose to catch up.

Overdose

In the event of overdose (symptoms may include dizziness, drowsiness, or dry mouth), symptomatic and supportive measures are recommended. Gastric lavage may be considered if ingestion was recent. Fexofenadine is not effectively removed by hemodialysis. Contact a poison control center or seek emergency medical attention.

Storage

Store at room temperature (20–25°C or 68–77°F), in a dry place, away from direct light and moisture. Keep the bottle tightly closed. Do not use after the expiration date printed on the packaging.

Disclaimer

This information is intended for educational purposes and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any new medication or changing your treatment plan.

Reviews

Clinical studies and post-marketing surveillance consistently report high patient satisfaction with Allegra, citing its effectiveness, lack of drowsiness, and convenience of once- or twice-daily dosing. Many users note significant improvement in quality of life during allergy season. Healthcare professionals appreciate its safety profile and reliability in both adult and pediatric populations.