The best cure is to raise your bars up to within an inch of your saddle. A more upright riding position reduces the pressure on your hands. If that is unacceptable to you, then consider bolting on a set of aerobars so you can give your hands some time off the bars.
I also like either Specialized Body Geometry or Louis Garneau gloves. Something with large separate pads for each side of the palm. But raising the bars is the most effective solution.