Ketanserin concentration-effect relationships in individual hypertensive patients.

1. This study further investigates the relationship between ketanserin concentration and the fall in BP in individual hypertensive patients. 2. An integrated kinetic-dynamic model was used to characterise the response to ketanserin for each individual in terms of BP reduction per unit drug concentration and to describe the temporal discrepancy for the plasma concentration-effect relationship (keq). 3. Using the linear effect model ketanserin concentrations were well correlated with the fall in BP in individual patients. There was a significant reduction in the responsiveness to ketanserin (m) after 1 month: -0.25 mm Hg ng-1 ml-1, compared with -0.47 following the 1st dose. 4. There was a significant increase in keq from 0.49 (1st dose) to 1.86 h-1 (1 month). 5. There was no relationship between the responsiveness to ketanserin and patient age, starting BP or peripheral alpha-adrenoceptor blockade.