Study in Elderly Alzheimer's Patients to Assess Skin Tolerability, Irritation With 3, 7-Day Applications of DTP-System

Inclusion Criteria: * Male or female at least 65 years of age. * Established dose of Aricept 10 mg at least 2 months prior to enrollment. * Established diagnosis of stable Alzheimer's disease treated with oral Aricept * Must be willing to change from oral Aricept to DTP (and placebo patch). * Body mass index of at least 18 and a minimum weight of at least 45 kg. * Blood pressure (sitting) must be diastolic \<95mmHg, and systolic \<145, stable for at least 3 months. Patients with well-controlled hypertension (with medication) may enroll as long as 3-month stability criterion is met. * Those with stable cardiac disease may be enrolled provided the patient has been on appropriate medication for 3 months prior to screening. Those with a pacemaker may be enrolled. * Pulse rate between 45 - 100 bpm; respirations between 8 - 20 per minute. * Those with thyroid disease may enroll if stable on treatment for at least 3 months prior to screening, and maintain the same dose of thyroid medication throughout the study. * Must have a caregiver who is either living with the patient or is in daily contact with the patient, agrees to be present at all visits, provide information as required, and ensure compliance with the medication schedule. * Free from any abnormality at Screening which may compromise the patient's ability to participate. * Free of any dermatologic conditions, excessive hair or skin allergies and sensitivities. * Male patients who have female partners of childbearing potent…