What are the recommended antiallergic (anti-allergic) medications for treatment?

Recommended Antiallergic Medications for Treatment

For allergic rhinitis, intranasal corticosteroids are the most effective first-line treatment, with intranasal antihistamines as an alternative or combination therapy for moderate-to-severe disease; oral second-generation antihistamines (loratadine, cetirizine, desloratadine, fexofenadine) serve as effective options when intranasal therapy is not tolerated, while oral leukotriene receptor antagonists should not be used as primary therapy due to inferior efficacy. 1

Allergic Rhinitis Treatment Hierarchy

First-Line Agents

Intranasal Corticosteroids (Most Effective)

• Intranasal corticosteroids provide superior symptom control compared to all other medication classes for allergic rhinitis 1
• These agents effectively reduce nasal congestion, rhinorrhea, sneezing, and nasal itching 1
• Examples include fluticasone propionate (200 mcg daily) and other formulations 1

Intranasal Antihistamines (Highly Effective Alternative)

• Rapid onset of action makes these particularly useful for episodic symptoms or pre-exposure prophylaxis 1
• Available agents include:
  • Azelastine 0.1% (137 µg per spray): 1-2 sprays twice daily for ages ≥6 years 1
  • Azelastine 0.15% (205.5 µg per spray): 1-2 sprays twice daily for ages ≥6 years 1
  • Olopatadine 0.6% (665 µg per spray): 1-2 sprays twice daily for ages ≥6 years 1
• Common side effects include bitter taste, epistaxis, somnolence, and headache 1
• Somnolence rates (0.9%-11.5%) overlap with oral antihistamines (1.3%-14%) and placebo (0.3%-10%) 1

Combination Therapy for Moderate-to-Severe Disease

Intranasal Corticosteroid + Intranasal Antihistamine

• For patients aged ≥12 years with moderate-to-severe seasonal allergic rhinitis, combination therapy may be recommended for initial treatment 1
• Fluticasone propionate plus azelastine (available as single combination spray Dymista: 137 µg azelastine + 50 µg fluticasone per spray) provides superior symptom reduction 1
• Studies show absolute symptom reductions of -5.31 to -5.7 on a 24-point scale versus -3.84 to -5.1 for fluticasone alone 1
• This represents >40% relative improvement compared to monotherapy 1

Oral Second-Generation Antihistamines

When Intranasal Therapy Not Tolerated or Preferred

These agents are less effective than intranasal corticosteroids but provide reasonable symptom control with minimal sedation 1, 2:

Loratadine

• Dosing: 10 mg once daily (maximum 10 mg/24 hours) for adults and children ≥6 years 3
• Children 2-5 years: 5 mg once daily 3
• Minimal sedative effects at recommended doses 3, 4
• Fast onset of action, once-daily dosing 4
• Caution: Sedation possible with higher-than-recommended doses 3

Cetirizine

• Dosing: 10 mg once daily for adults and children ≥6 years 5, 6
• Highly selective H1-receptor antagonist with rapid onset 7
• May cause mild sedation even at recommended doses (unlike loratadine, fexofenadine, desloratadine) 3
• Blocks eosinophil infiltration at allergen sites 7
• Proven efficacy in children ages 6-11 years with seasonal allergic rhinitis 6

Desloratadine

• Second-generation antihistamine with proven efficacy for seasonal and perennial allergic rhinitis 8
• Non-sedating at recommended doses 3, 8
• Safe at up to nine times the recommended dose without cardiovascular effects 8
• No drug-food interactions 8

Fexofenadine

• Non-sedating at recommended doses 3
• Appropriate for patients requiring complete avoidance of sedation 2

Agents NOT Recommended as Primary Therapy

Oral Leukotriene Receptor Antagonists (Montelukast)

• Should NOT be offered as primary therapy for allergic rhinitis 1
• Intranasal corticosteroids demonstrate clinically meaningful superior efficacy compared to montelukast for nasal symptom reduction 1
• May be considered only when patients cannot tolerate intranasal therapy or have concurrent mild persistent asthma 1
• Cost-effectiveness concerns given inferior efficacy 1

First-Generation Antihistamines (Diphenhydramine, Chlorpheniramine)

• Produce significant sedation and cognitive impairment 2
• Worsen sleep architecture 2
• Should be avoided in favor of second-generation agents 2

Anaphylaxis Treatment (Different Context)

Critical Distinction: For acute allergic emergencies/anaphylaxis, the treatment paradigm differs entirely:

First-Line: Epinephrine IM

• Epinephrine is the ONLY first-line treatment for anaphylaxis 1
• Dosing: 0.01 mg/kg IM (1:1,000 solution), maximum 0.5 mg 1
• Auto-injector: 0.15 mg for 10-25 kg; 0.3 mg for >25 kg 1
• May repeat every 5-15 minutes as needed 1

Adjunctive Only (Never Substitute for Epinephrine):

• H1 antihistamines (diphenhydramine 1-2 mg/kg, max 50 mg) relieve only itching and urticaria—NOT stridor, wheezing, or shock 1
• H2 antihistamines (ranitidine 1 mg/kg) may be added but minimal evidence supports use 1
• Combination H1 + H2 antihistamines superior to H1 alone 1
• Corticosteroids (prednisone 1 mg/kg, max 60-80 mg) may prevent biphasic reactions but have 4-6 hour onset—not helpful acutely 1
• Albuterol for bronchospasm resistant to epinephrine 1

Key Clinical Pitfalls

Common Errors to Avoid:

• Never substitute antihistamines for epinephrine in anaphylaxis—antihistamines do NOT treat airway edema, bronchospasm, or hypotension 1
• Do not use first-generation antihistamines (diphenhydramine, chlorpheniramine) for routine allergic rhinitis due to sedation and impairment 2
• Do not prescribe montelukast as first-line therapy for allergic rhinitis—it is significantly less effective than intranasal corticosteroids 1
• Exceeding recommended antihistamine doses increases sedation risk without proportional benefit 3
• Patients with severe renal or hepatic impairment require cautious dosing of oral antihistamines 3