Allergo Tablet, Syrup, Eye Drops

Allergo Hydrochloride is an antihistamine with selective peripheral H1 receptor antagonist activity. It inhibits histamine release from peritoneal mast cells. No anticholinergic, α-1 adrenergic or β-adrenergic receptor blocking effects has been observed. No sedative or other central nervous system effect has been observed. It does not appear to cross the blood brain barrier. 

Allergo is rapidly absorbed after oral administration with peak plasma concentration being reached in 2-3 hours. Elimination half-life of about 14 hours has been reported although this may be prolonged in patients with renal impairment.


It is used for the relief of symptoms associated with seasonal and perennial allergic rhinitis and chronic idiopathic urticaria.

Allergo is also used to associated treatment for these conditions: Allergic Rhinitis (AR), Chronic Idiopathic Urticaria, Seasonal Allergic Rhinitis, Antihistamine


Trade Name Allergo
Generic Fexofenadine
Fexofenadine Other Names Carboxyterfenadine, Fexofenadina, Fexofenadine, Terfenadine acid metabolite, Terfenadine carboxylate, Terfenadine-COOH
Weight 4mg, 2mg/5ml, 2%
Type Tablet, Syrup, Eye Drops
Formula C32H39NO4
Weight Average: 501.6564
Monoisotopic: 501.287908741
Protein binding

Fexofenadine is 60-70% bound to plasma proteins, primarily to albumin and α1-acid glycoprotein. The extent of protein binding is decreased to 56-68% and 56-75% in patients with renal and hepatic impairment, respectively.

Therapeutic Class Non-sedating antihistamines
Manufacturer Agio Pharmaceuticals, Therapeutics Bangladesh Ltd, Fdc Limited
Available Country India, Bangladesh
Last Updated: June 23, 2021 at 9:00 am


Fexofenadine Structure


Allergo dosage


  • Allergic rhinitis: 120 mg once daily or 60 mg twice daily
  • Urticaria: 180 mg once daily


  • 2-11 years: 30 mg (1 spoonful) or 5 ml twice daily
  • 6 months-2 years: 15 mg (1/2 spoonful) or 2.5 ml twice daily

In case of decreased renal function, care should be taken in dose selection and it may be useful to monitor renal function.

Side Effects

Allergo is generally well tolerated. The most commonly reported adverse events are headache, drowsiness, nausea, and dizziness. The incidence of these events observed with Allergo hydrochloride was similar to that observed with placebo.


Studies in the elderly, patients with hepatic impairment and patients with cardiac disease exposed to Allergo showed no statistically significant differences compared to healthy individuals. As with most new drugs there is only limited data in the elderly and renally or hepatically impaired patients. Allergo hydrochloride should be administered with care in these special groups.


Co-administration of Allergo Hydrochloride with either ketoconazole or erythromycin may cause increased plasma concentration of Allergo. Antacid containing Aluminium and Magnesium may reduce the absorption of Allergo. Fruit juices such as grapefruit, orange and apple may reduce the bioavailability of Allergo.

Food Interaction

  • Avoid fruit juice. Fruit juices like grapefruit, orange, and apple may reduce bioavailability and overall exposure to the medication.
  • Take with or without food. Co-administration with food does not significantly affect absorption.

Volume of Distribution

The volume of distribution is approximately 5.4-5.8 L/kg.

Half Life

The terminal elimination half-life is approximately 11-15 hours.


The oral clearance of fexofenadine is approximately 50.6 L/h and the renal clearance is approximately 4.32 L/h.

Pregnancy & Breastfeeding use

Pregnancy Category B. There are no adequate and well controlled studies in pregnant women. Allergo should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Lactation: It is not known if Allergo is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Allergo is administered to a nursing woman.


Allergo is contraindicated in patients with known hypersensitivity to Allergo or any of the ingredients of Allergo Hydrochloride.

Special Warning

Studies in special risk groups (elderly, renally or hepatically impaired patients) indicate that it is not necessary to adjust the dose of Allergo Hydrochloride in these patients.

Acute Overdose

In case of an overdose, standard measures to remove any unabsorbed drug should be employed. Symptomatic and supportive treatment is recommended. There has been no reported case of an acute overdose of Allergo hydrochloride.

Storage Condition

Store Allergo at controlled room temperature 20-25 °C. Keep all medicines away from reach of children.

Innovators Monograph

Allergo contains Fexofenadine see full prescribing information from innovator Monograph