Do antihistamines have a role in acute colds?

Antihistamines Have Minimal to No Role in Acute Colds

Antihistamines should not be routinely used for acute colds because they provide no clinically meaningful benefit on the primary symptoms of nasal congestion, runny nose, or sneezing, and any short-term effect on overall symptom severity is minimal and disappears after two days. 1, 2

Evidence Summary: Why Antihistamines Don't Work for Common Colds

The most recent high-quality evidence demonstrates that:

• Second-generation antihistamines (loratadine, cetirizine, fexofenadine) are completely ineffective for common cold symptoms and should never be prescribed for this indication 1, 3

• First-generation antihistamines show only a marginal short-term benefit: 45% of patients report improvement on days 1-2 versus 38% with placebo, but this small difference disappears by days 3-4 2

• Individual nasal symptoms show no clinically significant improvement: While first-generation antihistamines may produce statistically significant reductions in rhinorrhea and sneezing, these differences are not clinically meaningful in practice 1, 2

Critical Distinction: Common Cold vs. Upper Airway Cough Syndrome

This is where clinical judgment becomes essential:

If the patient has a pure viral common cold, antihistamines are not recommended 1

However, if the patient develops post-viral upper airway cough syndrome (UACS) with persistent cough, throat clearing, or postnasal drip sensation lasting beyond the typical cold duration, then first-generation antihistamines combined with decongestants become the evidence-based treatment of choice 4, 3

Treatment Algorithm for Post-Viral Symptoms:

• Days 1-7 of cold symptoms: Do not prescribe antihistamines; the cold is self-limiting 4

• Days 7-14 with persistent cough/postnasal drip: Consider UACS and initiate first-generation antihistamine plus decongestant (e.g., dexbrompheniramine 6 mg + pseudoephedrine 120 mg twice daily) 4, 3

• After 2 weeks of appropriate treatment without improvement: Obtain sinus imaging to evaluate for bacterial sinusitis or consider alternative diagnoses like asthma 3

Why First-Generation Antihistamines Work for UACS But Not Colds

The mechanism explains the paradox:

• First-generation antihistamines work through anticholinergic properties, not antihistamine effects, which is why they help with post-nasal drip and cough but not acute cold symptoms 4, 3

• Second-generation antihistamines lack anticholinergic activity, explaining their complete ineffectiveness for both conditions 4, 3

Pediatric Considerations: Strong Contraindication

Antihistamines should not be used in children under 6 years of age for common cold symptoms due to lack of efficacy and significant safety concerns 1

• Controlled trials show antihistamine-decongestant combinations are ineffective for upper respiratory infection symptoms in children 1

• The two pediatric trials evaluating antihistamines in acute rhinosinusitis showed no benefit over placebo 4

Side Effects That Outweigh Minimal Benefits

Common adverse effects include:

• Sedation is the primary concern, though meta-analyses question whether this differs significantly from newer agents 4, 3

• Anticholinergic effects: dry mouth, transient dizziness, urinary retention (especially in older men), and increased intraocular pressure in glaucoma patients 4, 3

• Performance impairment can occur even without subjective awareness of sedation, affecting work and driving 3, 5

Better Alternatives for Acute Cold Symptoms

Instead of antihistamines, consider:

• Nasal saline irrigation: Benefits with minimal side effects, especially in children 1

• Oral/nasal decongestants: Small positive effect on nasal congestion in adults 1

• NSAIDs: Effective for headache, ear pain, muscle/joint pain, and may improve sneezing 1

• Ipratropium bromide nasal spray: Specifically effective for rhinorrhea 4, 1

Common Clinical Pitfall to Avoid

Do not confuse allergic rhinitis with the common cold. If the patient has underlying allergic rhinitis that is exacerbated during a cold, antihistamines may help the allergic component but will not treat the viral cold itself 4, 1

The key clinical decision point: Determine if the condition is truly a common cold or allergic rhinitis before prescribing antihistamines 1

Guideline Consensus

The European Position Paper on Rhinosinusitis (2020) explicitly states that based on very low quality evidence, they cannot advise on the use of antihistamines in post-viral acute rhinosinusitis 4

The Journal of Allergy and Clinical Immunology (2005) confirms: There are no data presently to recommend the use of H1 antihistamines in acute bacterial sinusitis 4