Can drug interactions be evaluated by monitoring plasma drug concentrations?

摘要

If an 0ATP1B1/1B3 inhibitor is co-administered with a statin, then the plasma concentration of the latter can increase several-fold; however the pharmacological activity will not change significantly. In fact, alteration of the pharmacological effect of pravastatin with its chronic administration has not been observed in subjects with OATP1B1 polymorphisms. This is considered to be caused by the absence of large variations in the drug concentration at the target sites. In addition, it is theoretically proven that the inhibition of uptake transporters results in smaller changes in the tissue concentration than in the plasma concentration.