Comparisons of pharmacokinetics of glimepiride in combination with Ojeok-san versus glimepiride alone: an open-label, one-sequence, two-treatment controlled clinical study

Glimepiride remains a cost-effective antidiabetic treatment despite its potential risks. However, its interaction with traditional medicines like Ojeok-san (OJS), a commonly used herbal medication, warrants investigation. This open-label, fixed-sequence, two-period, two-treatment crossover study involved 17 healthy male volunteers. Subjects received glimepiride 4 mg once daily for 2 days in period 1, followed by OJS 4.35 g three times daily for 8 days, with concurrent glimepiride administration on the final two days in period 2. Co-administration of OJS with glimepiride resulted in pharmacokinetic changes. The mean area under the plasma concentration-time curve (AUC) from dosing to 24 h post-dosing (AUC_{0-24 h}) of glimepiride decreased from 1283.53 ng∙h/mL to 1125.27 ng∙h/mL, and the mean maximum concentration (C_max) reduced from 250.76 ng/mL to 209.38 ng/mL when compared to glimepiride alone. OJS co-administration also prolonged the median time to reach maximum concentration (T_max) and half-life (t_1/2). The study demonstrated pharmacokinetic interactions between glimepiride and OJS, showing reduced systemic exposure and altered elimination patterns of glimepiride during co-administration.