I went to my GP today and he's changed me antidepressant from pristiq 50 to lexapro 10 I have to wait 3days to start the new one. What difference can I expect with lexapro and what can I expect from not taking pristiq in the next 3days??? He told me that it should be easy as I was only on them for 10 days but already I'm feeling apprehensive about the next 3 days.