RECRUITMENT OF PARTICIPANTS IS PERFORMED ONLY BY STUDY SITES

INCLUSION CRITERIA:

Participants must meet the following inclusion criteria to be eligible.

• Male or Female (age over 55 years). Females must be non-child-bearing potential. Male patients with female partners of child-bearing potential should use effective contraception for the duration of the Study.
• A diagnosis of probable Alzheimer's disease established in accordance with the National Institute of Neurological and Communicative Disorders and Stroke /Alzheimer's disease and Related Disorders Association (NINCDS-ADRDA) classification.
• Severity of dementia of mild to moderate as assessed by the Mini-Mental State Examination (MMSE) score of 12-24.
• Patients must be living in the community living with or have at least daily visits from a responsible carer. The carer should be capable of assisting with the patient's medication, and prepared to attend with the patient for assessment.
• Written consent should be obtained from the patient and responsible carer.

EXCLUSION CRITERIA

Patients will not be eligible to participate in the study if they meet any of the following criteria:

• Primary, secondary or pseudodementias other than probable Alzheimer's disease.
• Clinically significant and/or uncontrolled condition or other significant medical disease.
• If taking medication for symptoms of dementia, the patient must be stable on therapy and have been taking these for a minimum of 3 months prior to enrolment.
• Treatment within the previous 3 months with any drug known to have a well defined potential for hepatotoxicity.
• Non-steroidal or steroidal anti-inflammatory agents. However, patients stable on low dose aspirin (upto 300mg/day) for at least 3 month prior to enrolment will be eligible.
• Taking anti-oxidant supplements.
• Active smokers of tobacco.
• Considered to be malnourished (body mass index <19).
• Patients in whom a lumbar puncture is contra-indicated.