Is it possible for me to take pristiq (desvenlafaxine) in the evening?

Yes but not common. It is possible to take desvenlafaxine in the evening although it is thought that both venlafaxine and desvenlafaxine both have an activating quality that can sometimes interfere with sleep in some patients. I would talk with your doctor about how you are taking to be sure they are aware. These medications can raise blood pressure and intuitively this seems incompatible with sleep. Stay safe!