This switch is designed for ultrasound applications where it passes only transient currents and drives capacitive loads. The high currents mentioned in the data-sheet (1A) are intended to be driven for a very short time (<<1% of the time). The average power is normally low and well below the package limits. The abs max power dissipation of the package is 1.8W at 70ºC. so with an analog signal of around 200V you would have 1.8W/200V = 9mA max., the data-sheet mentions a typical of 5mA (for other Vnn/Vpp but the idea is similar). If the application requires paralelling several channels, the skew among switches that are programmed ON can be assume to have a skew in the ns range.