INDICATION AND DOSAGE OF 

CHLORPHENIRAMINE MALEATE

What It Is

Chlorpheniramine maleate is a first-generation antihistamine commonly used to alleviate symptoms of allergic reactions. It is frequently included in over-the-counter medications for its ability to manage conditions such as allergic rhinitis and urticaria (hives). This medication functions primarily by blocking the effects of histamine, a chemical in the body responsible for many allergic symptoms.

Dosage Forms and Strengths

Chlorpheniramine maleate is available in several dosage forms, including:

• Tablets: Typically 4 mg per tablet.
• Extended-release Tablets: Usually 8 mg or 12 mg per tablet.
• Syrups: Available in concentrations of 2 mg/5 mL.
• Chewable Tablets: Often 2 mg per tablet for children.

These forms and strengths may vary depending on the manufacturer and country.

Brand and Generic Names

Chlorpheniramine maleate is marketed under various brand names, including:

• Chlor-Trimeton (by Pfizer)
• Teldrin (by PDL BioPharma)
• Dph (by Alvogen)

The generic name is simply Chlorpheniramine Maleate.

Indications for Use

Chlorpheniramine maleate is primarily indicated for the treatment of:

• Allergic Rhinitis: Symptoms include sneezing, itching, runny nose, and nasal congestion.
• Urticaria (Hives): Helps to relieve itching and rash.
• Allergic Conjunctivitis: Reduces itching and redness in the eyes.
• Common Cold Symptoms: Often included in combination with other medications to alleviate cough and cold symptoms.

Mechanism of Action

Chlorpheniramine maleate works by antagonizing histamine H1 receptors. Histamine is a neurotransmitter released during allergic reactions that binds to H1 receptors, leading to symptoms such as itching, swelling, and increased mucus production. By blocking these receptors, Chlorpheniramine maleate prevents or reduces these symptoms.

Administration and Dosage

The dosage of Chlorpheniramine maleate depends on the specific condition being treated, the age of the patient, and the dosage form used. Typical dosages include:

• Adults: 4 mg every 4-6 hours, not to exceed 24 mg per day.
• Children: Dosage is usually adjusted based on age and weight, often starting at 2 mg every 4-6 hours as needed, not to exceed 12 mg per day.

For extended-release formulations, the dosage may be less frequent, such as 8 mg every 8-12 hours.

Side Effects and Precautions

Common side effects of Chlorpheniramine maleate include:

• Drowsiness: This is a frequent side effect and can affect daily activities.
• Dizziness: May impair coordination and concentration.
• Dry Mouth: Due to its anticholinergic properties.
• Constipation: Another common anticholinergic effect.

Less common but serious side effects may include:

• Allergic Reactions: Rare but can occur.
• Difficulty Urinating: Especially in those with pre-existing urinary tract issues.
• Confusion: Particularly in elderly patients.

Precautions should be taken in patients with:

• Glaucoma: May exacerbate symptoms.
• Prostate Enlargement: Can worsen urinary symptoms.
• Liver Disease: Dosage adjustments may be needed.

Chlorpheniramine maleate should be used cautiously in combination with alcohol or other central nervous system depressants, as it can enhance drowsiness and impair cognitive functions.

Conclusion

Chlorpheniramine maleate is a widely used antihistamine effective in treating a range of allergic symptoms. Its availability in various dosage forms allows for flexible administration tailored to patient needs. While generally effective, it does come with potential side effects, particularly drowsiness, and should be used with caution in specific populations. As with any medication, it is crucial to follow dosing guidelines and consult healthcare professionals if any adverse effects or concerns arise.