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Chlorpheniramine Maleate (Piriton)

Chlorpheniramine Maleate (chlorphenamine) is an antihistamine used to relieve allergy symptoms, hay fever, and the common cold.

Last Modified: 21 May 2024

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What is Chlorpheniramine Maleate? 

Chlorpheniramine Maleate (chlorphenamine) is an antihistamine used to relieve allergy symptoms, hay fever, and the common cold. These symptoms include a runny nose, watery eyes, itching, and sneezing. 

Chlorpheniramine Maleate is a synthetic alkylamine derivative, produced through a chemical synthesis process. As a first-generation antihistamine, it works by blocking the actions of (1) histamine (specifically H1), a chemical in the body that causes allergic symptoms and (2) acetylcholine (to some extent) a neurotransmitter that causes dryness of the skin, mouth and mucous membranes, increased heartbeat, constipation, blurred vision and neurological effects. 

Global Name

Generic Names:

The generic name for the medication is chlorpheniramine (chlorphenamine) maleate. 

Global Brand Names:

  • 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 - is a well-known brand in the United Kingdom and Hong Kong. 
  • Chlorohistol – The brand name commonly available in the Middle East and India 


What is Chlorpheniramine Maleate used for? 

Chlorpheniramine Maleate is used to treat: 

  • 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? 


Chlorpheniramine Maleate is available in tablet form, syrup, and as an injectable solution. 

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. 


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

Who cannot take Chlorpheniramine Maleate?

  • Children: Not recommended for newborns or premature infants. 
  • Adults: Those with severe hypertension or severe coronary artery disease should avoid it. 
  • Elderlies: May be more prone to dizziness, hypotension, and sedation. 
  • Pregnancy and Lactation: Consult a healthcare provider; use only if clearly needed. 

Allergies and unsuitability:

Individuals allergic to chlorpheniramine or any of its components or other antihistamines should not take this medication. 

Interactions and contraindications:

Chlorpheniramine Maleate can interact with sedatives, MAO inhibitors, and alcohol. It is contraindicated in individuals with narrow-angle glaucoma, peptic ulcer, and prostate hypertrophy.

Side Effects

Common side effects include drowsiness, dizziness, constipation, blurred vision, and dry mouth/throat. 

Pharmacist Tips

  • Starting Chlorpheniramine Maleate: Begin with the lowest dose and increase only if necessary. 
  • Missed Dose: If you miss a dose, take it as soon as possible, but not close to the next dose. 
  • Alcohol Consumption: Avoid alcohol as it can increase the sedative effects. 
  • Storage Information: Store at room temperature, away from light and moisture. 
  • Regular Checkups: If symptoms persist or worsen, seek medical advice. 
  • Adherence to Therapy: Do not exceed the recommended dose and duration of treatment. 
  • Diet Considerations: Drink plenty of fluids unless otherwise directed to prevent dehydration. 

Consult your healthcare provider for personalized advice or if you have any questions about using Chlorpheniramine Maleate. 


Where is Chlorpheniramine Maleate available in Hong Kong?

Chlorpheniramine Maleate is an over-the-counter (OTC) medication that can be sold without a prescription. It is found in all chain drug stores, including Mannings and Watsons.


Can Chlorpheniramine Maleate be taken for a long time?

It is typically used for short-term relief. Prolonged use should be discussed with a healthcare provider. 

Is Chlorpheniramine Maleate non-drowsy?

No, drowsiness is a common side effect. 

Is Chlorpheniramine Maleate (Piriton) available for purchase over-the-counter?

Yes, it is available over-the-counter, but it's important to follow the dosage instructions on the package or as instructed by a physician. 

This website provides content related to drug use and medicine for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Do not use the information on this website to diagnose or treat a health problem or disease without consulting a qualified healthcare provider. The website's owners and contributors are not liable for any repercussions, adverse effects, or consequences resulting from the use of any medication or information provided herein.

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