Allergex Syrup, Tablet

Allergex is an alkylamine antihistamine. It is one of the most potent H1 blocking agents and is generally effective in relatively low doses. Allergex is not so prone to produce drowsiness, readily absorbed from the gastro-intestinal tract, metabolised in the liver and excreted usually mainly as metabolised in the urine.


Indicated mainly in allergic conditions including urticaria, sensitivity reactions, angioneurotic oedema, seasonal hay fever, vasomotor rhinitis, cough, common cold, motion sickness.

Allergex is also used to associated treatment for these conditions: Allergic Contact Dermatitis, Allergic Reaction, Allergic Rhinitis (AR), Allergic cough, Allergies, Allergies caused by Serum, Allergy to House Dust, Allergy to vaccine, Angioneurotic Edema, Asthma, Bronchial Asthma, Bronchitis, Common Cold, Conjunctival congestion, Conjunctivitis, Conjunctivitis allergic, Cough, Cough caused by Common Cold, Coughing caused by Flu caused by Influenza, Drug Allergy, Eye allergy, Fever, Flu caused by Influenza, Food Allergy, Headache, Headache caused by Allergies, Itching of the nose, Itching of the throat, Migraine, Nasal Congestion, Nasal Congestion caused by Common Cold, Pollen Allergy, Productive cough, Pruritus, Rash, Rhinorrhoea, Seasonal Allergic Conjunctivitis, Sinus Congestion, Sinusitis, Sneezing, Transfusion Reactions, Upper Respiratory Tract Infection, Upper respiratory tract hypersensitivity reaction, site unspecified, Urticaria, Vasomotor Rhinitis, Acute Rhinitis, Allergic purpura, Conjunctival hyperemia, Dry cough, Excess mucus or phlegm, Itchy throat, Mild bacterial upper respiratory tract infections, Ocular hyperemia, Throat inflammation, Upper airway congestion, Upper respiratory symptoms, Watery eyes, Watery itchy eyes, Airway secretion clearance therapy


Trade Name Allergex
Generic Chlorpheniramine
Chlorpheniramine Other Names Chlorophenylpyridamine, Chlorphenamin, Chlorphenamine, Chlorphenaminum, Chlorpheniramine, Chlorpheniramine polistirex, Chlorpheniraminum, Clorfenamina, Clorfeniramina
Weight 2mg/5ml, 4mg, 2mg/5ml
Type Syrup, Tablet
Formula C16H19ClN2
Weight Average: 274.788
Monoisotopic: 274.123676325
Protein binding


Therapeutic Class Sedating Anti-histamine
Manufacturer Jalalabad Pharmaceuticals Ltd, Nabiqasim Industries (pvt) Ltd,
Available Country Bangladesh, Pakistan
Last Updated: June 23, 2021 at 11:18 am


Chlorpheniramine Structure


Allergex dosage

Adults: 4 mg 3-4 times daily.


  • Up to 1( one) year: 1 mg twice daily
  • 1-5 years: 1 mg 3-4 times daily
  • 6-12 years: 2 mg 3-4 times daily or as directed by the physician

Side Effects

Drowsiness, dizziness, headache, psychomotor impairment, urinary retention, dry mouth, blurred vision and gastro intestinal disturbances, paradoxical stimulation may rarely occur, especially in high dosage or in children.


Allergex may produce mild sedation and it is advised that patients under continuous treatment should avoid operating machinery. Not recommended during pregnancy & lactation.


Alcohol, CNS depressants, anticholinergic drugs, MAOIs.

Food Interaction

  • Avoid alcohol.
  • Take with food.

Half Life

21-27 hours

Pregnancy & Breastfeeding use

Pregnancy Category B. Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).


There is no definite contraindication to therapy. It should be used with caution in epilepsy, prostatic hypertrophy, glaucoma and hepatic disease. The ability to drive or operate machinery may be impaired.

Innovators Monograph

Allergex contains Chlorpheniramine see full prescribing information from innovator // generic/chlorpheniramine/chlorpheniramine-maleate-injection-prescribing-information" Monograph