I am a 43 year old woman with anxiety disorder. I ve been on citalopram 20mg for a long time , recently I have starting having panic attacks again and he increased my citalopram to30 mg. the increase took me longer than I liked to get used to and I started to feel better . Then Out of the blue I started having rapid heart rate at night so my doctor started me on atenolol 25mg , I took first dose last night and today I felt crappy . I am hesitant to continue but the doctor told me to give it a chance ?