The primary analyses will be the calculation of trough to peak ratios (T/P ratios) for DBP and SBP. The T/P ratio will be calculated on the basis of changes in hourly means (related to dosing time) from baseline (DeltaHM). Trough is defined as the mean of the last three hours of the 24-hour dosing interval. Peak is the greatest reduction in hourly means in hours 2 to 8 after dosing. Thus, T/P is calculated as T/P = mean(DeltaHM22 - DeltaHM24)/min (DeltaHM2 - DeltaHM8).