The goal of this clinical study is to evaluate satisfaction with the use of orodispersible Memantine (OD) versus conventional Memantine tablets (MTb) using the validate SATMED-Q in patients with moderate to severe Alzheimer's disease. Due to the neurocognitive impairment associated with these stages of the disease, treatment satisfaction will be assessed indirectly through the primary caregiver.

The main questions this study seeks to answer are:

• Is caregiver satisfaction higher with OD (Sinolvir®) compared with MTb?
• What adverse events or side effects occur in patients receiving memantine in either pharmaceutical form?

Researchers will compare OD (Sinolvir®) and MTb to identify differences in caregiver satisfaction and to describe the adverse events reported. Satisfaction will be evaluated across the six domains of the SATMED-Q questionnaire, and results will be summarized by domain and by pharmaceutical dosage form.

All adverse events reported during the study will be documented.

Participants will receive Sinolvir®(OD) or Eutebrol® (MTb) daily, according to dosing regimens determined by the treating physicians based on the approved prescribing information. The duration of participation will be two months.

After two months of treatment, eligible primary caregivers will complete the SATMED-Q questionnaire. Caregivers will be invited to participate at Visit 1 and will complete the satisfaction questionnaire at Visit 2, which will be conducted between days 60 and 70 after Visit 1.

Inclusion Criteria:

• Patients with a diagnosis of Alzheimer's disease were selected according to the criteria of the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA).
• Patients had moderate to severe Alzheimer's disease, based on the following assessments:

Mini-Mental State Examination (MMSE) score ≤ 18 in patients with more than 12 years of education; or Montreal Cognitive Assessment (MoCA) score ≤ 18 in patients with more than 12 years of education.

Katz Index of Activities of Daily Living score ≤ 6 and Lawton Instrumental Activities of Daily Living scale score < 6 out of 8.

Clinical Dementia Rating (CDR) scale score of 2 or 3.

• Patients were considered eligible when memantine was selected as the therapeutic option for Alzheimer's disease, according to the treating physician's clinical judgment.
• Only patients who were prescribed memantine for the first time were included.
• Patients were included if they attended the clinical visit accompanied by their primary caregiver, and if the caregiver agreed to participate and signed the corresponding informed consent.
• The primary caregiver had Spanish as their native language or demonstrated functional proficiency in the language.

Exclusion Criteria:

• Patients with a diagnosis of preclinical Alzheimer's disease were excluded.
• Patients with a diagnosis of Alzheimer's disease at a stage other than moderate to severe were excluded, based on any of the following scales:

Mini-Mental State Examination (MMSE) score > 18; or Montreal Cognitive Assessment (MoCA) score > 18.

• Patients with uncontrolled depression (including major depressive disorder) within the last three months were excluded, according to:

Geriatric Depression Scale (GDS) (Yesavage), short form, score ≥ 10.

• Patients with uncontrolled anxiety within the last three months were excluded, according to:

Hamilton Anxiety Rating Scale (HAM-A) score ≥ 8.

• Patients with contraindications or any other condition preventing the use of memantine, in accordance with the approved prescribing information for SINOLVIR® or EUTEBROL®, were excluded.
• Primary caregivers who refused to participate or who were unable to complete the study due to severe sensory impairment or for any other reason were excluded.
• Patients with psychiatric disorders or symptoms of non-Alzheimer's disease origin that were active or decompensated at study entry (e.g., delirium, schizophrenia) were excluded.
• Patients with active alcohol use at study entry were excluded.
• Patients with unstable or uncontrolled neurological conditions, such as active autoimmune or infectious encephalitis, uncontrolled epilepsy, uncontrolled multiple sclerosis, or uncontrolled amyotrophic lateral sclerosis, were excluded.
• Patients with active brain neoplasms at study entry were excluded.