[Current issues on gastroesophageal reflux disease]

Effectiveness analysis of herbal medicine for gastroesophageal reflux disease: A retrospective study

This study aimed to identify the clinical features of gastroesophageal reflux disease (GERD) in primary clinics and the effectiveness and safety of herbal medicine (HM). Thirty-five patients with gastroesophageal-reflux symptom who visited the 16 Korean medicine (KM) primary clinics from June 2022 to October 2022 were included in the study. We retrospectively analyzed the charts of 35 patients and collected clinical characteristics, HM, and outcome variables such as the numerical rating scale, gastroesophageal reflux disease questionnaire, frequency scale for symptoms of gastroesophageal reflux disease, Euro-Quality Of Life-5 Dimension, and adverse events. Of the 35 patients, 12 (34.3%) were men, and the average age of all patients was 47.0 ± 14.3 years. HM was prescribed for all 35 patients; Pinelliae Tuber (n = 31, 88.57%), Zingiberis Rhizoma Recens (n = 30, 85.71%), and Poria Sclerotium (n = 28, 80%) were the most prescribed herbs. All scores including numerical rating scale, frequency scale for symptoms of gastroesophageal reflux disease, gastroesophageal reflux disease questionnaire, and Euro-Quality Of Life-5 Dimension after 30 and 60 days from baselines showed significant improvement, and there were only a few adverse events. This study supports the effectiveness and safety of HM in reducing GERD symptoms in primary Korean medicine clinics. The most frequently used herbs may play significant roles in GERD symptom management.

Development of Physiologically Based Pharmacokinetic Model for Orally Administered Fexuprazan in Humans

Fexuprazan is a new drug candidate in the potassium-competitive acid blocker (P-CAB) family. As proton pump inhibitors (PPIs), P-CABs inhibit gastric acid secretion and can be used to treat gastric acid-related disorders such as gastroesophageal reflux disease (GERD). Physiologically based pharmacokinetic (PBPK) models predict drug interactions as pharmacokinetic profiles in biological matrices can be mechanistically simulated. Here, we propose an optimized and validated PBPK model for fexuprazan by integrating in vitro, in vivo, and in silico data. The extent of fexuprazan tissue distribution in humans was predicted using tissue-to-plasma partition coefficients in rats and the allometric relationships of fexuprazan distribution volumes (V_SS) among preclinical species. Urinary fexuprazan excretion was minimal (0.29-2.02%), and this drug was eliminated primarily by the liver and metabolite formation. The fraction absorbed (Fa) of 0.761, estimated from the PBPK modeling, was consistent with the physicochemical properties of fexuprazan, including its in vitro solubility and permeability. The predicted oral bioavailability of fexuprazan (38.4-38.6%) was within the range of the preclinical datasets. The C_max, AUC_last, and time-concentration profiles predicted by the PBPK model established by the learning set were accurately predicted for the validation sets.