Endothelial Facilitation in Alzheimer's Disease

Inclusion Criteria:

- Subjects must have mild Alzheimer's Disease or Mild Cognitive Impairment (MCI);

- age between 55-85;

- Mini Mental Status Exam (MMSE) between 15-26;

- a caregiver who can provide information, and bring patient to the sessions;

- no known allergies to any of the medications to be used;

- normal renal function; willingness of patient and spouse/responsible caregiver to
participate.

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.