Evaluation on immediate analgesic efficacy and safety of Kai-Hou-Jian spray (children’s type) in treating sore throat caused by acute pharyngitis and tonsillitis in children: study protocol for a randomized controlled trial

BACKGROUND: Acute pharyngitis and tonsillitis are common respiratory diseases for which children seek medical care. Their main clinical manifestation is sore throat which interferes with patients’ quality of life. However, there is no proven effective or safe method to treat it. It is necessary to find an excellent strategy to reduce sore throat and reduce the burden of acute illness. We designed the randomized controlled trial with the characteristics of traditional Chinese medicine (TCM) to determine the clinical positioning of Kai-Hou-Jian spray (children’s type) (KHJS) through evidence-based research. This trial aims to evaluate the immediate analgesic efficacy of KHJS on sore throat caused by acute pharyngitis and tonsillitis (wind-heat syndrome/heat exuberance in lung and stomach syndrome) in children and to observe its safety. METHODS/DESIGN: This is a prospective, multicenter, randomized, double-blind, parallel-group, placebo-controlled trial. It will include 240 children with acute pharyngitis/tonsillitis from 7 study sites across China. All participants are randomly assigned to two parallel treatment groups, one with KHJS and the other with placebo sprays, for 5 consecutive days. The primary outcome is the time of analgesic onset. Secondary outcomes include duration of analgesic effect, area under time curve of 0–3 h Wong-Baker FACES Pain Rating Scale (WBS) score (AUC0-3 h), rate of analgesic onset, rate of disappearance of sore throat, changes of WBS score (in days), effective rate of pharyngeal signs, and effective rate of TCM syndrome. The incidence of adverse events during the trial is the primary safety outcome. In addition, vital signs and laboratory tests before and after medication are monitored. DISCUSSION: To our knowledge, this will be the first clinical trial to explore the immediate analgesic efficacy of a Chinese patent medicine spray for acute pharyngitis/tonsillitis induced sore throat in children in a multicenter, randomized, double-blinded, parallel-group, placebo-controlled manner. Not only might it prove the efficacy and safety of KHJS in the treatment of sore throat caused by acute pharyngitis/tonsillitis in children, but it might also provide evidence for the treatment of acute sore throat with Chinese herbal medicine. TRIAL REGISTRATION: A multicenter, randomized, double-blind, very low-dose, parallel controlled trial for the immediate analgesic effect and safety of Kai-Hou- Jian spray (children's type) in the treatment of sore throat caused by acute pharyngitis and tonsillitis in children. Chinese Clinical Trial Registry ChiCTR2000031599. Registered on 5 April 2020 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05148-1.