In a patient with seasonal allergic rhinitis not responding to loratadine (Claritin) and intranasal fluticasone (Flonase), can montelukast (Singulair) be added?

Adding Montelukast to Loratadine and Fluticasone for Seasonal Allergies

Before adding montelukast (Singulair), you should first switch from the oral antihistamine (Claritin) to an intranasal antihistamine combined with the Flonase, as this combination is significantly more effective than adding montelukast.

The Evidence-Based Treatment Algorithm

Step 1: Optimize Current Therapy First

The 2017 Joint Task Force guidelines make a strong recommendation that intranasal corticosteroids alone (like your Flonase) should be the initial treatment, NOT combined with oral antihistamines 1. The evidence shows no proven benefit of adding oral antihistamines like Claritin to intranasal steroids for initial treatment 1.

Step 2: Best Option for Inadequate Response

For moderate to severe seasonal allergic rhinitis not responding to intranasal corticosteroids alone, add an intranasal antihistamine (like azelastine) to the Flonase rather than adding montelukast 1. Studies show this combination produces:

• Greater symptom reduction than either agent alone
• Absolute improvements of 40% or more compared to monotherapy
• Clinically meaningful differences in total nasal symptom scores 1

Step 3: Where Montelukast Fits

Montelukast is FDA-approved for seasonal allergic rhinitis 2 and does provide statistically significant benefit over placebo. However, the guidelines give a strong recommendation that intranasal corticosteroids are superior to leukotriene receptor antagonists like montelukast 1, 3.

You can add montelukast if:

• The patient refuses or cannot tolerate intranasal antihistamines
• The patient has concurrent mild persistent asthma (though it wouldn't be first-line for either condition alone) 1
• The patient strongly prefers oral medication despite lesser efficacy 1

Important Caveats

The combination of intranasal steroid + montelukast has limited evidence. One high-quality study showed that adding montelukast to fluticasone in patients with residual symptoms was no more effective than placebo 4. Another study found fluticasone alone was superior to the combination of cetirizine plus montelukast 5.

Recent FDA warnings: Montelukast carries neuropsychiatric adverse effect warnings that should factor into your decision 6. Reserve it for selected patients where benefits clearly outweigh risks.

Practical Recommendation

1. First, ensure proper Flonase technique (spray away from septum, adequate duration of at least 2 weeks)
2. Add intranasal azelastine to the Flonase (available as combination spray Dymista or separate sprays)
3. Discontinue the oral Claritin as it adds no benefit to intranasal steroids 1
4. Only consider montelukast if the patient refuses intranasal antihistamine or has concurrent asthma

The hierarchy of evidence clearly shows: intranasal corticosteroid + intranasal antihistamine > intranasal corticosteroid alone > intranasal corticosteroid + oral antihistamine ≈ intranasal corticosteroid + montelukast 1, 4, 5.