Two studies have been carried out specifically to examine the speed of onset of action of intranasal
nedocromil sodium 1% (Tilarin) for the relief of symptoms due to ragweed
allergic rhinitis. One, a multicentre placebo-controlled comparative study using a QID regimen, 1 spray per nostril, was designed to assess the speed of onset of action of
nedocromil sodium during the first week of treatment in patients with
rhinitis symptoms, and to evaluate the efficacy and safety of
nedocromil sodium during 6 weeks of treatment (1). A 1-week baseline, the start of which was timed to coincide with the start of the ragweed season, was followed by 6 weeks double-blind trial treatment; only patients (n = 166) who were symptomatic at the end of baseline were included in the double-blind phase. Non-parametric analyses of all variables including a summary score (stuffy
nose, runny nose, itchy nose and
sneezing) showed that the onset of action of
nedocromil sodium occurred on the first day of treatment. Further, patients using
nedocromil sodium had less symptoms during the 10 days of peak pollen, at which time physician assessment showed reduced mucosal oedema and nasal discharge, and both patient and clinician opinions favoured
nedocromil sodium. No significant adverse events were reported during this 6-week study. In the second study (2), 104 patients were randomly allocated to receive either
nedocromil sodium or placebo, QID. They then spent 10 hours per day for 2 consecutive days in Iowa City Park during the peak of the ragweed season. Only patients showing significant symptoms of
seasonal allergic rhinitis (SAR) during 3 hourly baseline assessments were included. Over the 2-day period, symptom scores for stuffy
nose, runny nose, itchy nose and
sneezing, and global symptom summary scores, were recorded at 19 hourly time points. At home in the evening, patients recorded symptom scores for the post-exposure period. In comparison with placebo,
nedocromil sodium significantly improved
rhinitis symptoms within 2 hours, and this reduction in SAR symptoms was maintained throughout the 2-day exposure period. Post exposure symptom summary scores were also significantly lower in patients treated with
nedocromil sodium than in those patients treated with placebo. Overall, very few adverse events were reported, none of them serious. In conclusion,
nedocromil sodium 1%
nasal spray acts rapidly, within 2 hours on the first day of treatment, to reduce ongoing symptoms of SAR. Relief of
rhinitis symptoms is maintained throughout the peak pollen period with
nedocromil sodium QID, which appears to be a safe and well tolerated treatment for ragweed SAR.