Chlorpheniramine  (Chlorphenamine)

Please note: these are basic guidelines, refer to your doctor for a professional medical opinion.

Popular brand names:

Allergex, Rhineton

Popular combinations:

Demazin (paediatric syrup), Flusin DM, Rinex

Drug group:

Antihistamine

Prescription needed?

No

What does it do?

Chlorpheniramine is used to treat a variety of allergic conditions:

• Allergic conjunctivitis, urticaria (hives), insect bites/stings: relieves itching/swelling/redness
• Hay fever and common cold: reduces sneezing, runny nose and itching eyes
• Angioedema
• It can be used intravenously with adrenaline to prevent or treat allergic reactions to blood transfusions/X-ray contrast material, and acute allergic shock (anaphylaxis)

How does it work?

• Chlorpheniramine blocks H1-histamine receptors, reducing the release of histamine (a mediator in allergic reactions)
• It also has mild anticholinergic actions, which suppresses mucus secretion

How should it be used?

Take chlorpheniramine with food or drink to reduce gastrointestinal irritation

What is the typical dosage?

Your doctor will recommend a dosage tailored to your need, but typically:

Total daily adult dose: 24mg, taken in 1-4 divided doses

How quickly will it start to work?

Oral preparations – symptom relief within 60 minutes
               

How long will the effects last?

4–6 hours
     

When should I stop using it?

Can be safely stopped when no longer needed

Is it safe for prolonged use?

No problems expected                                                 

What are the possible side effects?

The following have been reported:

• More common: drowsiness
• Less common: dry mouth, blurred vision, difficulty in passing urine (anticholinergic effects)
• Report to your doctor before taking your next dose if you experience: severe headaches, rash, extreme excitability (children)

What other considerations are important?

Dosage may be adjusted by your doctor under certain conditions.

• Certain health problems: liver problems, asthma, epilepsy or seizures, glaucoma, urinary difficulties eg. prostate enlargement
• Other medicines: other drugs with anticholinergic effects, phenytoin, monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants, sedatives
• Pregnancy and breast-feeding: Safety in pregnancy not established, may cause drowsiness and poor feeding in a breastfed baby
• Children: Reduced dose necessary
• Over 60: Reduced dose may be necessary, increased likelihood of adverse effects
• Driving and hazardous work: Caution, may cause drowsiness, dizziness, and blurred vision
• Alcohol: Avoid, may increase the sedative effects of the drug