A Chinese traditional medicine, sho-saiko-to (xiao-chaihu-tang), reduces the bioavailability of tolbutamide after oral administration in rats.
The effects of Sho-saiko-to on the pharmacokinetics of tolbutamide were investigated in rats. After intravenous administration of tolbutamide (5 mg/kg), no significant change in the pharmacokinetics of tolbutamide was observed in both groups of single and multiple (7 days) pre-administration of Sho-saiko-to (500 mg/kg). In the study of single oral administration of tolbutamide (50 mg/kg), co-administration of Sho-saiko-to tended to accelerate the initial absorption rate of tolbutamide. The area under the plasma concentration-time curve of tolbutamide after oral administration was significantly reduced by Sho-saiko-to. Subsequently, a significant decrease was observed in the oral bioavailability of this drug when Sho-saiko-to was given concomitantly. These findings suggest that Sho-saiko-to reduces the bioavailability of tolbutamide after oral administration in rats, and that this change is not related to hepatic metabolism.
Nishimura
N
N
Department of Pharmacy, Shimane Medical University Hospital, Japan.
Naora
K
K
Hirano
H
H
Iwamoto
K
K
D000465:Algorithms; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D019540:Area Under Curve; D001682:Biological Availability; D004347:Drug Interactions; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000493:pharmacokinetics*; D007275:Injections, Intravenous; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014044:Tolbutamide / Q000493:pharmacokinetics*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004365:Drugs, Chinese Herbal; D007004:Hypoglycemic Agents; C018142:saiko-keishi-to; D014044:Tolbutamide