Hi Peggy, Thank you for your question. There can be side effects when Prozac is stopped suddenly, instead of gradually tapered. These side effects may include racing heartbeat, dry mouth, increased sweating, stomach upset (burping, bloating, constipation, diarrhea, gas, indigestion), dizziness, headache, shaking, as well as others. Every medication affecs each person differently, so some patients may have all of the above symptoms (and more) while other patients have no problems. I recommend not stopping any medications without first speaking to your doctor, who should be able to tell you the best way to stop taking the medication. Best of luck, Casey