Imrecoxib is a novel, moderately selective cyclooxygenase-2 (COX-2) inhibitor with anti-inflammatory and analgesic properties, commonly used in patients with osteoarthritis. However, pharmacokinetic data to guide its use in the elderly are currently lacking.This study aimed to evaluate the pharmacokinetics of imrecoxib and its primary metabolites and to assess its safety in healthy elderly subjects.Nineteen healthy participants, including 10 non-elderly and 9 elderly individuals, received a single 100 mg oral dose of imrecoxib under fasting conditions. Pharmacokinetic parameters, safety, and tolerability were analyzed.Following a single 100 mg oral dose, imrecoxib was absorbed with a median time to peak plasma concentration (Tmax) of approximately 2 hours. Plasma concentration–time profiles of imrecoxib (M0) showed greater interindividual variability among elderly participants compared to non-elderly ones. In elderly subjects, peak plasma concentrations (Cmax) of M0, its hydroxyl metabolite M1, and carboxyl metabolite M2 increased by 39%, 21%, and 17%, respectively, while the area under the concentration–time curve from 0 to t (AUC0–t) rose by 34%, 13%, and 27%, respectively, compared with non-elderly subjects. The 90% confidence intervals for the geometric mean ratios of Cmax, AUC0–t, and AUC0–∞ of M0, M1, and M2 between the groups fell outside the 80–125% range, suggesting these pharmacokinetic parameters were not fully equivalent. Nevertheless, statistical comparison of M0, M1, and M2 pharmacokinetics revealed no significant differences (P > 0.05). Imrecoxib was well tolerated in both age groups, with particularly favorable gastrointestinal and cardiovascular safety profiles.The pharmacokinetic and safety data indicate that elderly healthy subjects do not require dose adjustments when using imrecoxib.
