Chlorpheniramine Maleate: Brands, Price & Uses in Bangladesh

Chlorpheniramine Maleate is a first-generation (sedating) H1-receptor antagonist antihistamine used for the symptomatic relief of a range of allergic and allergic-type conditions. Its indications can be classified by strength of evidence as follows:

Established / widely accepted uses

• Relief of symptoms of seasonal and perennial allergic rhinitis (hay fever), including sneezing, rhinorrhea (runny nose), and itching/watering of the eyes, nose, or throat.
• Relief of allergic conjunctivitis symptoms (itchy, watery eyes) associated with allergic rhinitis.
• Symptomatic relief of urticaria (hives) and pruritus (itching) of allergic origin.
• Adjunctive symptomatic treatment of allergic skin reactions and mild allergic reactions (e.g., insect bites, contact allergies), and as an adjunct to epinephrine in the management of anaphylaxis (it does not replace epinephrine, which remains the first-line treatment).

Combination-product / adjunct uses

• Chlorpheniramine Maleate is a common ingredient in multi-symptom cold and cough combination products (often paired with a decongestant and/or antitussive), where it is used to reduce sneezing and rhinorrhea associated with the common cold. In this setting it treats the allergic/histamine-mediated component of symptoms only and does not shorten the duration of a cold or treat its underlying viral cause.
• Sometimes used as a component of combination products intended for symptomatic relief of vasomotor rhinitis and mild upper respiratory allergy symptoms accompanying colds.

Off-label / less strongly supported uses

• Used off-label for prevention or relief of mild allergic-type reactions to blood transfusions or contrast media, generally as directed by a physician.
• Occasionally used off-label, at a physician's discretion, for mild allergic pruritus not otherwise specified.

Chlorpheniramine Maleate does not cure the underlying cause of allergies and provides temporary symptomatic relief only.

The dosing of Chlorpheniramine Maleate depends on the indication, patient age, and formulation used (immediate-release vs. sustained-release, tablet vs. syrup vs. injection). The following is a general guide; always follow the product label or a physician's/pharmacist's instructions.

Allergic rhinitis, urticaria, and other allergic conditions (oral, immediate-release)

Sustained/extended-release tablets

Where an extended-release formulation of Chlorpheniramine Maleate (e.g., 8 mg or 12 mg) is used, it is generally taken once or twice daily as directed on the product label; tablets should be swallowed whole and not crushed or chewed, as this can cause too much drug to be released at once.

Injection (adjunctive use, under medical supervision)

Chlorpheniramine Maleate injection is administered by a healthcare professional (intramuscular, subcutaneous, or slow intravenous injection), typically as an adjunct in the management of acute allergic reactions or anaphylaxis, at a dose and frequency determined by the treating clinician.

Renal/hepatic impairment

There is no well-established formal dose-adjustment schedule for renal or hepatic impairment; however, because Chlorpheniramine Maleate is hepatically metabolized and renally excreted, a lower dose or longer dosing interval, and closer monitoring for excess sedation or anticholinergic effects, is advisable in patients with significant hepatic or renal impairment, on physician advice.

Side effects of Chlorpheniramine Maleate are generally related to its sedating and anticholinergic properties.

Common

• Drowsiness, sedation, and dizziness (most common)
• Dry mouth, dry nose, and dry throat
• Blurred vision
• Constipation
• Thickening of bronchial/respiratory secretions
• Mild gastrointestinal upset (nausea, loss of appetite)

Less common

• Urinary retention or difficulty urinating
• Paradoxical CNS excitation - restlessness, nervousness, insomnia, or irritability (more common in children and the elderly rather than sedation)
• Headache, muscular weakness/incoordination
• Palpitations or mild tachycardia

Rare/serious

• Hypersensitivity reactions, including rash or, rarely, angioedema/anaphylaxis
• Blood dyscrasias (e.g., agranulocytosis, hemolytic anemia, thrombocytopenia) - rare, reported with prolonged use of antihistamines of this class
• Significant confusion or hallucinations, particularly in elderly patients

Patients should seek prompt medical attention for signs of a serious allergic reaction, severe confusion, difficulty breathing, or inability to urinate.