What over-the-counter (OTC) medications contain chlorpheniramine?

Over-the-Counter Medications Containing Chlorpheniramine

Chlorpheniramine is available in several over-the-counter (OTC) medications, primarily in cold and allergy products, often combined with decongestants like pseudoephedrine or pain relievers like paracetamol (acetaminophen). 1

Common OTC Formulations

Chlorpheniramine maleate (also called chlorphenamine) is found in:

• Single-ingredient antihistamine products:

  • Available as 4 mg tablets 1
  • Often labeled as "Chlor-Trimeton" or similar brand names

• Combination cold and allergy products:

  • With pseudoephedrine (decongestant) 2
  • With paracetamol (acetaminophen) and caffeine 3
  • In various multi-symptom cold and cough formulations

Dosage Forms

• Immediate-release tablets (typically 4 mg)
• Sustained-release/extended-release formulations (8-12 mg) 2
• Liquid formulations (syrup) - typically 2 mg/5 mL 4

Important Clinical Considerations

Classification and Effects

Chlorpheniramine is a first-generation H1 antihistamine with:

• Significant sedating properties 4
• Anticholinergic effects 5
• Potential SSRI (selective serotonin reuptake inhibitor) activity 6

Safety Concerns

• Sedation and impairment: First-generation antihistamines like chlorpheniramine can cause significant sedation and impair driving ability and cognitive function, even without subjective awareness of sedation 4

• Anticholinergic effects: May cause dry mouth, constipation, urinary retention, and blurred vision 4

• Special populations:

  • Hepatic impairment: Should be avoided in severe liver disease due to inappropriate sedating effects 4
  • Pregnancy: Often chosen by clinicians when antihistamine therapy is necessary during pregnancy due to its long safety record 4
  • Children: Use in children under 6 years is generally not recommended due to safety concerns 4

• Drug interactions: Potential for interactions with:

  • MAOIs (contraindicated)
  • CNS depressants (alcohol, sedatives) - enhanced sedation 4
  • Other anticholinergic medications - additive effects

Age Restrictions

• Not recommended for children under 6 years due to safety concerns and lack of efficacy data 4
• FDA advisory committees have recommended against OTC cough and cold medications containing antihistamines like chlorpheniramine in children under 6 years 4

Clinical Applications

While primarily used for allergic conditions, chlorpheniramine may be found in OTC products for:

• Seasonal and perennial allergic rhinitis
• Common cold symptoms
• Urticaria (hives)
• Addition to non-sedating antihistamines at night for urticaria patients to improve sleep 4

Important Warnings

• Sedation may persist beyond the intended dosing interval
• Impairment of driving and cognitive function can occur without awareness
• Concomitant use with alcohol or other CNS depressants significantly increases risk of impairment
• Anticholinergic effects may be problematic, especially in older adults

When recommending or using OTC chlorpheniramine products, patients should be advised of these potential effects and appropriate precautions should be taken, particularly regarding driving and operating machinery.