Decreased absorption of midazolam in the stomach due to low pH induced by coadministration of Banha-sasim-tang

• Published in: 환경독성보건학회지, 31(0) pp. 1 - 9
• Main Authors: 조준현, 김선주, 남웅식, 성은지, 이상규
• Format: Journal Article
• Language: English
• Published: 환경독성보건학회 01.06.2016
• Subjects: 기타의약학
• ISSN: 2093-6400

Objectives: Banha-sasim-tang (BST), which consists of seven different herbs, is one of the most popular herbal formulae for treating gastrointestinal disorders in Eastern Asia. The commonly used herbal medicine is often co-administered with other therapeutic drugs, which raises the possibility of herb–drug interactions and may modify the clinical safety profile of therapeutic drugs. Methods: We investigated the potential herb–drug interactions between BST extract and midazolam (MDZ) in mice. The area under the plasma concentration-time curve (AUC) of MDZ and 1ʹ-hydroxymidazolam (1ʹ-OH-MDZ) was evaluated for both oral and intra¬peritoneal administration of MDZ, following oral administration of BST (0.5 and 1 g/kg). Results: It was found that the AUC of MDZ and 1ʹ-OH-MDZ was lower in case of oral administration of MDZ. Administration of BST extract was not associated with hepatic cytochrome P450 activity. BST extract induced a strong reduction in pH and it has been reported that oral mucosal absorption of MDZ is lower at low pH. The decreased ab¬sorption rate of MDZ might be caused by the ingredients of BST and may not be related to other factors such as increased excretion of MDZ by P-glycoprotein. Conclusions: The altered pharmacokinetics of midazolam caused by co-administration with BST in vivo could be attributed to a decrease in pH and subsequent reduction of MDZ absorption rate. KCI Citation Count: 0