FIGURE 1.

Eighty minutes after the radioligand injection, most of the radioactivity in plasma still corresponded to parent compound. The metabolism of the radioligand was slower following pitolisant than after placebo. While for 5 subjects (shown in circles; means ± SD), the observations followed the typical hill function shape, for one of the participants (shown in square symbols), metabolism showed a different pattern. For this subject, the radioligand had lower radiochemistry purity in both scans