Chaihu Shugan pills slow down the absorption of Duloxetine, induce its metabolism, and reduce plasma exposure in beagle dogs.
The study was conducted on six adult healthy beagle dogs, selected randomly. These dogs were subjected to a single-dose administration of Duloxetine Hydrochloride. Afterwards, they were administered Chaihu Shugan pills orally, twice daily, for 15 consecutive days. This medication regimen was followed by another single-dose administration of the Duloxetine Hydrochloride, with the entire experiment using a self-control method for the dogs. All plasma samples from the dogs were treated similarly, and the concentrations of Duloxetine and its metabolite, 4-hydroxyduloxetine, were measured using a method established with ultra-performance liquid chromatography-tandem mass spectrometry.
Discussion of Results: The obtained data showed a decrease in the Duloxetine and 4-hydroxyduloxetine concentrations in the plasma samples of beagle dogs after the combination with Chaihu Shugan pills. The drug also induced the metabolism of these substances, shortening the time they remained in the system. The experiment demonstrated a linear relationship between Duloxetine and 4-hydroxyduloxetine concentrations, confirming the effectiveness of the applied ultra-performance liquid chromatography-tandem mass spectrometry method for simultaneously measuring plasma concentration of Duloxetine and its metabolite in beagle dogs. This indicates that Chaihu Shugan pills can influence Duloxetine absorption and metabolism.
