You should contact your doctor to ask him first -- but personally if my anxiety increased over 2-3 weeks consistently, I'd tell my doctor I want to go back to 10mg if that worked, or try something different.
From my experience generally side effects lessen over time -- not get worse.
QUOTE(NewQuestions @ May 13 2007, 09:53 AM)

How long will you guys try a new drug/dosage? I have been moving up on Lexapro from 10 to 20 mg over the past month and for the last 2 or 3 weeks it has increased my anxiety/jitteriness. Do I stay the course or give up?