Barbara, My husband, George, who has had PD for 8 years has been on clozaril for three weeks now. Our patient education pamphlet says possible side effects are - drowsiness, dizziness, constipation, increased saliva, dry mouth, headache, nausea, and changes in eyesight. He is definitely drowsy. He no longer drools. He was already constipated - so -. No complaints from him. It is working for us. The worst is the blood work every week. Good luck, Grace cg for George