Abstract
Abstract
Objectives:
The effect of chronic administration of etoricoxib (EXB), in the absence or presence of St. John’s Wort (SJW), on its pharmacokinetic parameters and blood pressure was investigated in rats.
Methods:
Rats were divided into 3 groups, each group received daily different oral treatment for 3 weeks. Rats’ blood pressures were monitored initially, after 1 and 3 weeks of treatment, and after 1 week of discontinuing dosing of both drugs. EXB pharmacokinetic parameters in the absence or presence of SJW were calculated after 3 weeks.
Key findings:
SJW was significantly affected EXB pharmacokinetic parameters. The steady state peak plasma concentration and terminal half-life were reduced by 32% and 91%, respectively, due to a > 3 fold increase in its apparent clearance which is a concentration and time dependent effect. EXB was significantly increased (P<0.001) Rats’ blood pressure while, co-administration of EXB and SJW was not significantly affect (P>0.05) rats’ blood pressure as compared to the control.
Conclusions:
Monitoring blood pressure of patients anticipated taking EXB for extended period should be advised. The co-administration of SJW with EXB should be avoided since SJW would greatly reduce EXB concentrations by inducing its metabolism.