This study aims to investigate bumetanide in patients with biologically confirmed Alzheimer's disease (AD). Bumetanide is a potent diuretic administered orally and is FDA approved for the treatment of edema and hypertension. Repurposing bumetanide as a medication for AD has been proposed based on data that demonstrated its ability to "flip" the APOE genotype-dependent transcriptomic signatures in AD mouse and cell culture models. Critically, this discovery was subsequently explored in Electronic Health Record cohorts, which revealed that among individuals over the age of 65, bumetanide exposure was significantly associated with a lower prevalence of AD in three independent datasets.

Primary Objective: To evaluate the safety and tolerability of bumetanide when administered to participants with biomarker-confirmed Alzheimer's disease.

Secondary Objective: To evaluate the clinical and biomarker effects of bumetanide in participants with mild cognitive impairment or mild dementia due to Alzheimer's disease.

Inclusion Criteria:

• Mild cognitive impairment or mild dementia due to Alzheimer's disease.
• Alzheimer's disease medications are planned to remain stable throughout.
• Willingness and ability to complete all aspects of the study including assessments, neuropsychological testing, and MRI.

Exclusion Criteria:

• Clinically significant abnormalities in screening laboratory tests
• Chronic liver disease
• Renal insufficiency
• Poorly managed hypertension
• Participants taking the following concomitant medications, based on the current Prescribing Information for bumetanide: lithium, drugs with ototoxic potential, drugs with nephrotoxic potential, probenecid, and indomethacin.