Prazosin Treatment for Disruptive Agitation in Alzheimer's Disease

This is a 24 week study with 14 visits to the research clinic. Approximately 6 of these
visits may be done by phone. Additional phone checks are scheduled at the beginning of each
12 week part of the study. Participants will have a 50:50 chance of being on prazosin or
placebo in the first 12 weeks of the study. For the second 12 weeks, all participants will
take prazosin.

Study visits include a physical and neurological exam; memory testing; interviews with the
caregiver about behaviors; and vital signs.

Inclusion Criteria:

- No age limit

- Probable or Possible Alzheimer's Disease

- Disruptive agitated behaviors at least twice a week (overly anxious or excited,
making offensive comments.....)

- Stable medications for 2 weeks

- Must have a caregiver who spends 10 hours per week caring for the participant and
agrees to participate in all evaluation sessions

Exclusion Criteria:

- Cardiovascular: unstable angina, recent myocardial infarction, preexisting
hypotension (systolic BP less than 110) or orthostatic hypotension (≥20 mmHg drop in
systolic BP following 2 minutes of standing posture)

- Any unstable medical condition

- Exclusionary medications: current treatment with prazosin, other alpha-1 blockers
(trazodone, sildenafil, vardenafil or tadalafil)

- Psychoactive medications: subjects may be psychoactive medication-free or be partial
responders (by subjective assessment of referring health care professional) to one
psychoactive medication from any of the following classes: antipsychotics,
anticonvulsants, mood stabilizers, antidepressants, benzodiazepines, or buspirone.
Partial response is defined as some improvement in agitated behavior but persistence
of agitated behaviors severe enough to cause patient distress and/or difficulty with
caregiving. Although not formally rated, this improvement is equivalent to a Clinical
Global Impression of Change rating of no more than minimal improvement (improvement
is noticed by not enough to improve patient function or caregiver's practical
management of the patient).

- Psychiatric/behavioral: lifetime schizophrenia; current delirium, mania, depression,
or uncontrolled persistent distressing psychotic symptoms (hallucinations,
delusions), substance abuse, panic disorder, or any behavior which poses an immediate
danger to patient or others or which results in the patient being too uncooperative
to meet the requirements of study participation.