What is the best over-the-counter (OTC) oral medication for severe seasonal allergies?

Best OTC Oral Medication for Severe Seasonal Allergies

For severe seasonal allergies, second-generation antihistamines like cetirizine (10mg daily) are the most effective OTC oral medication option, with loratadine as an alternative for patients who experience sedation with cetirizine. 1

Medication Options and Efficacy

Second-Generation Antihistamines

• Cetirizine (10mg):

  • Most effective for controlling sneezing, rhinorrhea, and nasal pruritus 1
  • Provides 24-hour relief of sneezing, runny nose, itchy/watery eyes, and itchy throat/nose 2
  • Demonstrated 36.7% reduction in total symptom complex scores versus 15.4% with loratadine and 12% with placebo 3
  • Faster onset of action (within 1 hour) compared to loratadine (3 hours) 3

• Loratadine:

  • Less effective than cetirizine in reducing rhinitis symptom scores 4
  • Less sedating than cetirizine in some patients 4
  • Once-daily dosing with onset within 1 hour and duration of at least 24 hours 5

Other OTC Options

• Oral Decongestants (pseudoephedrine, phenylephrine):
  • Help reduce nasal congestion through vasoconstriction 4
  • Should be used with caution due to side effects including elevated blood pressure, palpitations, irritability, and sleep disturbance 4
  • Not recommended for long-term use or in patients with hypertension, cardiac arrhythmias, glaucoma, or hyperthyroidism 4

Treatment Algorithm for Severe Seasonal Allergies

1. First-line: Start with cetirizine 10mg once daily

   • Most effective second-generation antihistamine for symptom control 1, 3
   • Provides 24-hour relief 2

2. If sedation occurs with cetirizine:

   • Switch to loratadine (less sedating but also less effective) 4, 5

3. For inadequate symptom control:

   • Consider adding an intranasal corticosteroid (most effective overall for allergic rhinitis) 4, 1
   • Intranasal corticosteroids are superior to oral antihistamines and leukotriene receptor antagonists for nasal symptom reduction 4

4. For predominant nasal congestion:

   • Add oral decongestant (pseudoephedrine) for short-term use only 4
   • Monitor for side effects, especially in patients with cardiovascular conditions 4

Important Considerations and Cautions

• Sedation risk: Cetirizine may cause mild drowsiness in some patients (13.7% vs 6.3% with placebo) 4
• Dosing: Higher doses of cetirizine (20mg) may provide better symptom control in severe cases but increase risk of sedation 6
• Contraindications: Use oral decongestants with caution in patients with hypertension, cardiac conditions, glaucoma, or hyperthyroidism 4
• Duration: The American Academy of Allergy, Asthma, and Immunology recommends continuing treatment for at least 3 months with periodic evaluation 1
• Combination therapy: Adding an oral antihistamine to an intranasal corticosteroid has not been proven to provide additional benefit over intranasal corticosteroid alone 4

Special Populations

• Older adults: More sensitive to psychomotor impairment from antihistamines; second-generation preferred 1
• Children: Second-generation antihistamines are safer; cetirizine is approved for ages 6 and older 2
• Patients with comorbid asthma: Consider treatment that addresses both conditions 1

For truly severe and refractory cases not responding to OTC medications, prescription options like intranasal corticosteroids should be considered as they are more effective than oral antihistamines for overall symptom control 4, 1, 7.