ABSTRACT
The Eb occupancies in response to increasing doses and plasma levels are presented in figure 1 and figure 2. In each case, a rectangular hyperbola provided a better fit (i.e., explained a greater degree of variance) than a simple linear fit. The parameters for the curves relating occupancy to dose were as follows: for risperi done, Occm.,x= 91 % , ED5o=0.8 mg/day, with 77% vari ance explained; for olanzapine, Occmax=92% , EDjo= 3.2 mg/day, with 81% variance explained; for cloza pine, Occmax=71 %, ED..;o=l 12 mg/day, with 55% vari ance explained. The parameters for the curves relating occupancy to plasma level were as follows: for risperi done, Occmjx=88%, ED5o=3.2 ng/ml, with 59% vari ance explained; for olanzapine, 0 c c max=90% , ED5o= 6.4 ng/ml, with 84% variance explained; for clozapine, O ccm;lx=68% , EDio=88 mg/day, with 18% variance explained. It is im portant to note that clozapine does not saturate rhe D2 receptors, and the theoretical m ax imum occupancy (O ccm3x) is 6 8 % -7 1 % . This is in contrast to risperidone and olanzapine, where we ob served occupancies of up to 83% and where Occmax was 91 % and 92% , respectively.
