This study evaluated AEs, discontinuation due to AEs, and effects on hemodynamic parameters, including systolic blood pressure (SBP) and aortic augmentation index (AIx), following multiple oral doses of MK-8266. Five serial panels, each consisting of eight participants (40 participants in Panels A, B, C, D, and E), were randomized to receive either MK-8266 or matching placebo twice daily (BID) or three times daily (TID) for 10 consecutive days. Although the original plan was to evaluate MK-8266 treatment in Panels D and E using both BID and TID regimens, the study actually evaluated identical TID regimens in these panels.