Side effects may vary for each individual depending on the person's disease state, age, weight, gender, ethnicity and general health. When side effects of a drug or medication are severe, the dosage may be adjusted or a second medication may be prescribed. Lifestyle or dietary changes may also help to minimize side effects. Patients can usually find the complete list of side effects with their medication. Serious side effects of ARICEPT may include: allergic reaction including hives, difficulty breathing, swelling of your face, lips, tongue, or throat, black, bloody, or tarry stools, coughing up blood or vomit that looks like blood or coffee grounds, painful or difficult urination, seizure (black-out or convulsions) nausea or vomiting, diarrhea, loss of appetite, muscle cramps, tired feeling, sleep problems (insomnia)