Doctor prescribed Paxil for panic disorder due to unbalanced chemicals in my brain. Tried Paxil for the first time today. Felt nervous and jittery a little. How long for the medication to have full effect of the body?? My panic attacks have reduced so much since last month. I was scared I called the ems for two straight weeks, constantly went to the doctors office, had tests run and everything normal. I am fearful a lot, paranoid, and full of worry. I fear having an attack everyday but try to think positive so that it won happen. It works sometimes. Paxil just leaves me jittery and even more anxious. Are those side effects? Or I just need time for the medicine to work? Please I need feedback from somebody with the same issues so that I won't have to keep getting my vitals checked.