Background: Acute pharyngitis accounts for an estimated 15 million patient visits in the United States. However, there is no proven effective and safe treatment. Although Chinese herbal medicine is widely used in the treatment of acute pharyngitis, there is a lack of evidence-based data. Despite several clinical trials conducted in this setting, no randomized placebo-controlled trial has been performed to date. This trial aims to investigate the efficacy and safety of Qi-Wei-Qing-Yan aerosol (QWQYA), a Chinese herbal prescription, compared with a placebo aerosol in the treatment of acute pharyngitis with lung-stomach excess-heat syndrome.

Methods/design: This is a prospective, multicenter, randomized, double-blinded, parallel-group, placebo-controlled trial. A total of 420 adult patients, of either sex, with acute pharyngitis will be enrolled from seven study sites across China. All patients will be randomly allocated to one of three parallel treatment groups: (1) QWQYA with the current propellant, (2) QWQYA with a previous propellant, and (3) the placebo aerosol with the current propellant. The study medication will be administered into the pharyngeal region in three sprays thrice daily for 5 consecutive days. The primary outcome measures are time to complete resolution of sore throat and relief rate of sore throat. Secondary outcome measures include resolution rate of sore throat, time to relief of sore throat, intensity of sore throat, and change of traditional Chinese medicine syndrome score and clinical signs score from baseline to post-treatment, as well as the occurrence of any adverse events.

Discussion: This will be the first clinical trial to investigate the efficacy and safety of QWQYA in the treatment of acute pharyngitis in an adult population in a multicenter, randomized, double-blinded, parallel-group, placebo-controlled manner. Not only might it establish the basis for the efficacy and safety of QWQYA in treating acute pharyngitis, but it might also provide evidence to support the use of Chinese herbal medicine in treating acute pharyngitis and thus support an alternative treatment option for management of acute pharyngitis.

Trial registration: Chinese Clinical Trial Registry ChiCTR-IPR-15005991.