Dexmedetomidine in the Treatment of Agitation Associated With Dementia (TRANQUILITY II)

Inclusion Criteria: 1. All subjects must have a diagnosis of probable AD based on NIA-AA criteria (2018) 2. Episodes of psychomotor agitation (e.g., kick, bite, flailing) 3. Subjects exhibit behaviors that are congruent with the International Psychogeriatric Association criterion for agitation representing a change from the subject's usual behavior 4. A score of 15 to 23 on the Mini-Mental State Exam (MMSE) 5. Subjects who read, understand, and provide written informed consent, or who have a LAR to provide consent on their behalf 6. Subjects who are deemed to be medically appropriate for study participation by the principal investigator 7. Participants who agree to use a medically acceptable and effective birth control method Exclusion Criteria: 1. Subjects with dementia or other memory impairment not due to probable AD. 2. Clinical diagnosis of probable AD should not be applied when there is evidence of a cerebrovascular incident temporally related to the worsening of cognitive function. 3. Subjects with agitation caused by acute intoxication. 4. Subjects with significant risk of suicide or homicide per the investigator's assessment. 5. Subjects who are medically unstable or in recovery. Note: Subjects with a remote (\>5 years) history of stroke may be included, regardless of size/location. 6. History of clinically significant syncope or syncopal attacks, orthostatic hypotension within the past 2 years, current evidence of hypovolemia, orthostatic hypotension, bradycardia. 7. Subjects who had a total score of \>13 (ie, high fall risk) on the John Hopkins Fall Risk Assessment Tool. 8. Subjects with laboratory or ECG abnormalities. 9. Subjects who have received an investigational drug within 30 days prior to Screening. 10. Subjects who are currently suffering from substance abuse. Patients with a potential cause for delirium (relatively recent onset agitation and dementia)