Efficacy and safety of Phlai capsule compared to placebo as the treatment in allergic rhinitis patients

Abstract

: Preclinical studies demonstrated anti-inflammatory effects of Phlai capsule containing Zingiber montanum (J.Koenig) Link ex A.Dietr. extract. However, its clinical effect on allergic rhinitis is not evident. : We sought to assess the efficacy and safety of Phlai for treating allergic rhinitis. : A randomized, double-blind, placebo-controlled study was conducted. Patients with allergic rhinitis were randomized into three groups and received 100 mg (compound D 4 mg) of Phlai capsule or 200 mg (compound D 8 mg) of Phlai capsule or placebo once a day for 4 weeks. The primary outcome was a change in the reflective total five symptom score (rT5SS). The secondary outcomes were the change in the instantaneous total five symptom score (iT5SS), the reflective individual symptom scores (rhinorrhea, nasal congestion, sneezing, itchy nose, itchy eyes), Rhinoconjunctivitis Quality of Life-36 Questionnaire (RCQ-36) score, peak nasal inspiratory flow, and adverse events. : Two hundred and sixty-two adult patients were enrolled. Compared with placebo, 100 mg of Phlai capsule improved rT5SS [adjusted mean difference (aMD) -0.62; 95% CI -1.22, -0.03; p = 0.039], rhinorrhea (aMD -0.19; 95% CI -0.37, 0.002; p = 0.048), itchy nose (aMD -0.24; 95% CI -0.43, -0.05; p = 0.011), and itchy eyes (aMD -0.19; 95% CI -0.36, -0.02; p = 0.033) at week 4. Nasal obstruction, sneezing, iT5SS, overall RCQ-36 score, peak nasal inspiratory flow did not reach statistically significance. 200 mg of Phlai capsule did not bring additional benefits compared to 100 mg. Adverse events were similar among groups. : Phlai was safe. At four weeks, there were small improvements in rT5SS, together with the individual symptoms of rhinorrhea, itchy nose, and itchy eyes. Phlai capsule can be a potential alternative treatment for patients with allergic rhinitis. Further randomized controlled studies are warranted to investigate the appropriate dosages and the long-term effects of Phlai capsule.