Rupatadine safe, effective for treating seasonal allergic rhinitis
Rupatadine at either 10 or 20 mg delivers superior improvements in nasal and ocular symptoms of seasonal allergic rhinitis (SAR) compared with placebo, with both doses well tolerated by adult and adolescent patients, according to the results of a phase III trial.
The trial randomized 900 SAR patients (mean age, 36.7 years; 50.8 percent male) from Japan to receive rupatadine 10 mg (n=298) or 20 mg (n=300) or placebo (n=302) for 2 weeks. The respective proportion of adolescent patients in the three treatment arms were 12.3 percent, 11.7 percent and 12.0 percent.
Following 2 weeks of treatment, the primary outcome of total 4 nasal symptom score (T4NSS; sneezing, rhinorrhoea, nasal congestion and nasal itching) showed a significantly greater decrease in the rupatadine arms than in the placebo arm (−1.085 for 10 mg and −1.415 for 20 mg vs −0.604; p<0.001 for both). [Allergol Int 2019;68:207-215]
Rupatadine consistently produced superior improvements in the secondary endpoints, as follows: total 2 ocular symptom score (T2OSS), total symptom score (TSS) and individual symptom scores.
In terms of safety, the 10- and 20-mg rupatadine doses were well tolerated. Adverse event (AE) rates were 6.6 percent with placebo, 14.1 with the lower rupatadine dose and 15.0 percent with the higher dose. Somnolence was the most commonly reported AE, with none of the AEs resulting in treatment withdrawal. There were no serious adverse drug reactions observed.
“The clinical benefit of rupatadine was immediate, and [both] doses significantly improved the nasal symptoms, starting on day 1. This means that the onset of action was observed 24 hours after the first dose intake,” the investigators noted.
“The performance of rupatadine 20 mg was generally better than that of rupatadine 10 mg, although their differences were not statistically significant for most of the efficacy variables investigated,” they added.
Given the general absence of marked efficacy differences, the investigators recommended using the 10-mg dose when initiating rupatadine treatment for most patients from a safety perspective. Meanwhile, the 20-mg dose can be a viable therapy for those with severe SAR symptoms.
“This option is supported by the finding that rupatadine 20 mg yielded a statistically better performance in alleviating nasal symptoms than rupatadine 10 mg in the subgroup of patients in the highest baseline disease severity category (T4NSS ≥14),” the investigators said.
They also acknowledged that the short treatment duration was a major limitation of the current trial. More studies are needed to determine the long-term risk–benefit profile of rupatadine, especially because patients with SAR take medications for several months.
Fast onset of action is highly desirable for antihistamines. A novel second-generation H1 antihistamine, rupatadine is readily absorbed following oral ingestion in humans, reaching the peak plasma concentration with a median time to peak concentration of 0.67–1.00 hour. These facts suggest rapid onset and extended duration of efficacy of the drug. [PLoS One 2016;11:e0163020]