What are the recommended medications for allergies?

Recommended Medications for Allergies

Severity-Based Treatment Algorithm

For mild allergic symptoms (itching, urticaria, rhinorrhea), second-generation H1 antihistamines are the preferred first-line treatment, with cetirizine 10 mg once daily or loratadine 10 mg once daily being optimal choices due to their rapid onset, minimal sedation, and proven efficacy. 1, 2

Mild Allergic Reactions (Urticaria, Itching, Mild Rhinitis)

Preferred medications:

• Cetirizine 10 mg once daily - fastest onset among second-generation antihistamines with minimal sedation 2
• Loratadine 10 mg once daily - onset within 1 hour, duration of at least 24 hours 1, 3
• Fexofenadine 180 mg once daily - completely non-sedating with no psychomotor impairment 2

Avoid first-generation antihistamines (diphenhydramine, chlorpheniramine) as primary therapy due to significant sedation, cognitive impairment, anticholinergic effects, and association with accidents and cardiac events 1, 4

Allergic Rhinitis

Treatment escalation based on symptom severity:

• Mild intermittent symptoms: Second-generation H1 antihistamines as needed 1
• Consistent mild-moderate symptoms: Intranasal corticosteroids (INCS) as monotherapy 1
• Moderate persistent symptoms: Daily INCS as preferred controller medication 1
• Severe symptoms: Combination therapy with INCS plus oral antihistamine and/or leukotriene receptor antagonist 1

Intranasal antihistamines (azelastine) are equal or superior to oral second-generation antihistamines for seasonal allergic rhinitis and can be used as first-line treatment 1

Anaphylaxis - Life-Threatening Allergic Reactions

This is the critical distinction where treatment differs dramatically from mild allergies:

First-line treatment (NO substitutes):

• Epinephrine 0.3-0.5 mg intramuscularly (anterolateral thigh) for adults and children >25 kg 5, 6
• Epinephrine 0.01 mg/kg IM (maximum 0.3 mg) for children ≤25 kg 5, 6
• Repeat every 5-15 minutes as necessary 5, 6

Adjunctive medications (never substitute for epinephrine):

• H1 antihistamines: Diphenhydramine 1-2 mg/kg (maximum 50 mg) IV/oral OR cetirizine 10 mg for less sedation 5, 1, 2
• H2 antihistamines: Ranitidine 1-2 mg/kg (maximum 75-150 mg) 5
• Corticosteroids: Prednisone 1 mg/kg (maximum 60-80 mg) oral or methylprednisolone 1 mg/kg IV to prevent biphasic reactions 5
• Bronchodilators: Albuterol nebulized (1.5 mL children, 3 mL adults) for bronchospasm 5

Critical Pitfalls to Avoid

The most dangerous error is using antihistamines instead of epinephrine for anaphylaxis. Antihistamines only relieve itching and urticaria - they do NOT treat stridor, shortness of breath, wheezing, GI symptoms, hypotension, or shock 5. Antihistamines reach peak concentration in 1-3 hours versus <10 minutes for IM epinephrine 7.

Never inject epinephrine into buttocks, digits, hands, or feet - only anterolateral thigh 6

First-generation antihistamines cause significant sedation and may decrease awareness of worsening anaphylaxis symptoms 5

Discharge and Long-Term Management

After anaphylaxis treatment:

• Prescribe two epinephrine auto-injectors with proper training 5, 1
• Continue adjunctive therapy for 2-3 days: H1 antihistamine every 6 hours, H2 antihistamine twice daily, corticosteroid daily 5
• Provide written anaphylaxis emergency action plan 5
• Refer to allergist for comprehensive evaluation 5, 1

Immunotherapy Consideration

For persistent symptoms despite optimal pharmacotherapy, allergen immunotherapy (subcutaneous or sublingual) should be considered when there is clear evidence of specific IgE sensitization to clinically relevant allergens 1