10mg/1ml Chlorpheniramine Injection / Chlorphenamine Maleate Injection

10mg/1ml Chlorpheniramine Injection / Chlorphenamine Maleate Injection

Product : Chlorpheniramine Maleate Injection

Specification : 10mg/1ml

Standard : BP, USP

Packing : 10 x 10amps/box

Description :

Chlorpheniramine is 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.

Indications and Usage :

Chlorphenamine injection is indicated for acute urticaria, control of allergic reactions to insect bites and stings, angioneurotic oedema, drug and serum reactions, desensitisation reactions, hayfever, vasomotor rhinitis, severe pruritus of non-specific origin.

Adults:

The usual dose of chlorphenamine injection for adults is 10mg to 20mg, but not more than 40mg should be given within a 24-hour period. The injection may be given by the subcutaneous, intramuscular or intravenous route.

When a rapid effect is desired, as in anaphylactic reactions, the intravenous route is recommended in addition to emergency therapy with adrenaline (epinephrine), corticosteroids, oxygen and supportive therapy as required. In this case chlorphenamine injection should be injected slowly over a period of one minute, using the smallest adequate syringe. Any drowsiness, giddiness or hypotension which may follow is usually transitory.

In the event of a blood transfusion reaction, a dose of 10mg to 20mg of chlorphenamine injection should be given by the subcutaneous route. This can be repeated to a total of 40mg within a 24-hour period, or oral forms of chlorphenamine may be given until the symptoms subside.

Chlorphenamine injection may be helpful in the prevention of delayed reactions to penicillin and other drugs when given separately by intramuscular injection immediately prior to administration of the other drug. The usual dose is 10mg.

Chlorphenamine injection cannot, however, be relied on to prevent anaphylactic reactions in patients known to be allergic to a particular drug.

Paediatric population:

The dose for children should be calculated, based on either the child's age or their body weight, using the following table:

Extra care should be taken when preparing the injection for children under 1 year due to the small volumes that are required. Dilution of chlorphenamine injection with sodium chloride intravenous infusion (0.9% w/v) should facilitate preparation. For example, diluting 0.2ml chlorphenamine injection to 2ml with sodium chloride 0.9% injection produces a solution containing chlorphenamine 1mg/ml.

Pharmacodynamics :

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.

Mechanism of action :

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.