Endothelial Facilitation in Alzheimer's Disease

Exclusion Criteria

• •Significant Psychiatric disorder;
• •stroke; current use of any of the test medications (e.g., statin, L-Arginine, Kuvan);
• •phenylketonuria (PKU) ;
• •elevated serum phenylalanine level (\>10 mg/dL);
• •allergy to any of the medications; current active malignancy;
• •renal insufficiency (elevated creatinine above 1.3mg/dl);
• •abnormal liver function (Alanine Aminotransferase (ALT) or Aspartate Transaminase (AST) 2x normal);
• •other serious disease including coronary insufficiency or congestive heart failure, carotid stenosis greater than 50%, active peptic ulcer, urinary tract or other active infection, cancer (except skin cancer, or 5 years inactive breast or prostate cancer )etc.;
• •pregnancy; or
• •inability to come to UMass for follow-up. Subjects may continue to take anticholinesterase drugs for Alzheimer's Disease (Aricept, Exelon, Razadyne) and/or Namenda, if they have been on the drug(s) for at least 3 months. Subjects on levodopa and male subjects taking drugs for erectile dysfunction (Viagra, Cialis, Levitra) are cautioned regarding hypotension.