Chlorpheniramine Maleate

A histamine H1 antagonist used in allergic reactions, hay fever, rhinitis, urticaria, and asthma. It has also been used in veterinary applications. One of the most widely used of the classical antihistaminics, it generally causes less drowsiness and sedation than promethazine.

Chlorpheniramine is a histamine-H1 receptor antagonist indicated for the management of symptoms associated with upper respiratory allergies.

For the treatment of rhinitis, urticaria, allergy, common cold, asthma and hay fever.

• 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

In allergic reactions an allergen interacts with and cross-links surface IgE antibodies on mast cells and basophils. Once the mast cell-antibody-antigen complex is formed, a complex series of events occurs that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H₁-receptors, produces pruritis, vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Chlorpheniramine, is a histamine H1 antagonist (or more correctly, an inverse histamine agonist) of the alkylamine class. It competes with histamine for the normal H₁-receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies.

Chlorpheniramine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.

Well absorbed in the gastrointestinal tract.

72%

21-27 hours

Oral LD50 (rat): 306 mg/kg; Oral LD50 (mice): 130 mg/kg; Oral LD50 (guinea pig): 198 mg/kg [Registry of Toxic Effects of Chemical Substances. Ed. D. Sweet, US Dept. of Health & Human Services: Cincinatti, 2010.] Also a mild reproductive toxin to women of childbearing age.

• Avoid alcohol.
• Take with food.

• 6-12 years: 2 mg every 4-6 hours, maximum 12 mg daily.
• 2-5 years: 1 mg every 4-6 hours, maximum 6 mg daily.
• 1-2 years: 1 mg twice daily.