Why are antihistamines (anti-allergic medications) used to treat cough in children?

From the Guidelines

Antihistamines are not recommended for treating cough in children due to limited evidence of effectiveness and potential side effects. The use of antihistamines in children with cough has been a topic of debate, but current medical guidelines discourage this practice. According to a study published in the Journal of Allergy and Clinical Immunology 1, the efficacy of cold and cough medications, including antihistamines, for symptomatic treatment of upper respiratory tract infections has not been established for children younger than 6 years. Furthermore, the study highlights the potential toxicity of these medications, with reports of fatalities associated with their use in children.

Key Points to Consider

• The sedating effects of antihistamines may make children drowsy, giving the impression that the cough is improving when the child is simply sleeping more 1.
• Potential side effects of antihistamines in children include drowsiness, dry mouth, blurred vision, and in some cases, paradoxical excitation in young children.
• For children with coughs, better approaches include ensuring adequate hydration, using honey (for children over 1 year), and employing saline nasal sprays for nasal congestion.
• The exception is when the cough is specifically caused by allergies, in which case newer, non-sedating antihistamines may be appropriate as part of allergy management under medical supervision.

Recommendations

• Avoid using antihistamines as a first-line treatment for cough in children.
• Consider alternative approaches, such as ensuring adequate hydration and using honey or saline nasal sprays, to manage cough symptoms in children.
• If the cough is caused by allergies, consult with a healthcare professional to determine the best course of treatment, which may include newer, non-sedating antihistamines.

From the FDA Drug Label

Uses temporarily relieves cough due to minor throat and bronchial irritation as may occur with a cold controls cough to help you sleep temporarily relieves these symptoms due to hay fever or other upper respiratory allergies: runny nose itching of the nose and throat sneezing itchy, watery eyes Purpose Cough suppressant Antihistamine

Antihistamines are used to treat cough in children because they can help relieve symptoms of upper respiratory allergies that may be causing the cough, such as hay fever. Additionally, some antihistamines have a cough suppressant effect, which can help control coughing [ 2(reference_id: 2) ] [ 2(reference_id: 2) ].

• Key points:
  • Relieve allergy symptoms that may cause cough
  • Have a cough suppressant effect The FDA label does not provide a detailed explanation of the mechanism, but it supports the use of antihistamines for relieving cough symptoms in children [ 2(reference_id: 2) ] [ 2(reference_id: 2) ].

From the Research

Antihistamines for Cough in Children

• Antihistamines are commonly used to treat symptoms that depend on histamine release, such as allergic diseases, including rhinitis, asthma, urticaria, and anaphylaxis 3.
• In the context of cough, antihistamines are sometimes prescribed, although their effectiveness for this specific use is not well established 4, 5.
• A study comparing the effect of honey, dextromethorphan, and diphenhydramine on nightly cough and sleep quality in children found that honey had a more alleviating effect on upper respiratory tract infection-induced cough compared to dextromethorphan and diphenhydramine 6.
• Another study evaluated the efficacy of a combination syrup of bilastine, dextromethorphan, and phenylephrine in cough relief in patients with cough associated with a common cold or allergy, and found it to be efficacious, safe, and non-inferior to another syrup containing chlorpheniramine maleate, dextromethorphan, and phenylephrine 7.

Effectiveness of Antihistamines for Cough

• A review of studies on over-the-counter medications for acute cough in children and adults found that there is no good evidence for or against the effectiveness of antihistamines in relieving cough symptoms 4.
• A Cochrane review on anti-histamines for prolonged non-specific cough in children found that the current data do not support the use of antihistamines as empirical therapy for children with chronic cough, although some studies suggest a clinical response may occur within 2 weeks of therapy 5.

Considerations for Use in Children

• Antihistamines can have adverse effects, especially in young children, and their use for cough should be balanced against these risks 3, 5.
• The safety profile of antihistamines, particularly in children under 2 years of age, is not well established, and many antihistamines are prescribed off-label in this age group 3.