Chlorpheniramine Maleate

What is Chlorpheniramine Maleate?

Chlorpheniramine Maleate is an over-the-counter medication widely used to relieve allergy symptoms, hay fever, and the common cold. These symptoms include a runny nose, watery eyes, itching, and sneezing.

As a first-generation antihistamine, it differs from newer classes by blocking the actions of both histamine (specifically H1) and, to some extent, acetylcholine. It is a synthetic alkylamine derivative, produced through a chemical synthesis process.

Generic Names:

• Chlorpheniramine Maleate: The widely recognised generic name used globally.
• Chlorphenamine: A common regional variation of the generic name used in several countries.

Global Brand Names:

Chlorpheniramine Maleate is sold under various brand names depending on the region.

• Chlor-Trimeton: This brand is commonly available in the United States.
• Aller-Chlor: Also found in the United States, available over the counter at many pharmacies.
• Chlorphen: The availability of this brand can be found in the United States and other countries.
• Allergy Relief: This is a common name for over-the-counter allergy medications and may be found in many countries, often as a store brand or generic label.
• Teldrin: Known in the United States, though "Teldrin" may not always contain chlorpheniramine.
• Piriton: Piriton is a well-known brand in the United Kingdom and Hong Kong.
• Chlorohistol: The brand name commonly available in the Middle East and India.

These names all refer to the same medication. It's important to note that while the active ingredient is the same globally, different countries may have different regulations and available medication formulations.

What is Chlorpheniramine Maleate used for?

Chlorpheniramine Maleate is used to relieve:

• Seasonal and perennial allergic rhinitis
• Allergic conjunctivitis
• Urticaria and angioedema
• Common cold and allergy symptoms
• Food and chemical allergies

How do you use Chlorpheniramine Maleate?

Availability:

• Tablet form
• Syrup
• Injectable solution

Suitability:

• Adults: Yes.
• Elderlies: Yes, but with caution due to increased sensitivity to side effects.
• Children: Yes, with adjusted dosages; use caution and under physician supervision for children aged 6 years and below.

Dosage Information:

• Adults: 4 mg every 4 to 6 hours, not to exceed 24 mg in 24 hours.
• Children: Dosage varies based on age and weight; consult a paediatrician for accurate dosing.

Who cannot take Chlorpheniramine Maleate?

• Newborns or premature infants
• Adults with severe hypertension or severe coronary artery disease
• Individuals allergic to chlorpheniramine or any of its components or other antihistamines

Allergies and unsuitability:

• Rare, but possible allergic reactions to chlorpheniramine or its components.

Warnings and precautions:

• Do not exceed the recommended dose and duration of treatment to avoid the risk of severe adverse neurological effects.
• Drink plenty of fluids unless otherwise directed to prevent dehydration.
• Take with or without food, but taking with food may reduce mild gastrointestinal discomfort.

Interactions and contraindications:

• Avoid alcohol to reduce the risk of increased sedative effects.
• Avoid sedatives and MAO inhibitors as they can interact dangerously with this medication.

Conditions where the drug should not be used:

• Narrow-angle glaucoma
• Peptic ulcer
• Prostate hypertrophy
• Severe hypertension
• Severe coronary artery disease

Common side effects of Chlorpheniramine Maleate include drowsiness, dizziness, constipation, blurred vision, and a dry mouth or throat. Elderlies may be more prone to experiencing dizziness, hypotension, and sedation.

Prolonged or excessive use beyond the recommended dosage can compound these side effects and lead to more severe neurological effects. If symptoms persist or worsen during treatment, seek medical advice.

Warnings and precautions:

• Do not exceed the recommended dose and duration of treatment to avoid the risk of severe adverse neurological effects.
• Drink plenty of fluids unless otherwise directed to prevent dehydration.
• Take with or without food, but taking with food may reduce mild gastrointestinal discomfort.

Interactions and contraindications:

• Avoid alcohol to reduce the risk of increased sedative effects.
• Avoid sedatives and MAO inhibitors as they can interact dangerously with this medication.

Conditions where the drug should not be used:

• Narrow-angle glaucoma
• Peptic ulcer
• Prostate hypertrophy
• Severe hypertension
• Severe coronary artery disease

Storage information:

• Store at room temperature.
• Keep away from light and moisture.
• Keep in a safe place away from children.

Handling instructions:

• Begin with the lowest dose and increase only if necessary.
• Use the measuring device that comes with the liquid medication to ensure the correct dose.
• Take a missed dose as soon as possible, but skip it if it is close to the time for the next scheduled dose.

Where is Chlorpheniramine Maleate available in Hong Kong?

Chlorpheniramine Maleate is classified as an "Over-the-Counter" (OTC) medication, meaning it can be sold freely without a prescription.

Patients can legally obtain this medication at all general chain drug stores, including prominent retailers like Mannings and Watsons.