Interaction mechanisms pharmacokinetic phase

Pharmacokinetics When EE was administered in combination with Drag XYZ, arithmetic mean 11/2 and Tmax values were comparable for both treatments. Geometric mean Cmax and AUCo-24values were approximately 20 % to 30 % lower, respectively, than when EE was administered with placebo. For AUCq-24, the lower and upper limit of the 90 % Cl were below the pre-defined 90% Cl of 0.8-1.25. Therefore, a pharmacokinetic interaction between Drug XYZ and EE can be concluded. The mechanism for this statistically significant reduction in systemic exposure to EE is unknown, however, since Drag XYZ is known to induce CYP 1A2 in man, and CYP 1A and phase II enzymes in animals, the observed effect could reflect a metabolic interaction between Drag XYZ and EE. 

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