MEDical CANnabis for Improving Symptoms During Severe DEMentia Disorders in Long-term Care Facility in Geneva

The study design is a placebo-controlled cross-over trial. The patients, the relatives, the health care professionals, and the study staff will be blinded.

Medical cannabis treatment is a cannabis oil that contains THC and CBD in a 1:2 ratio. The initial dose of 7 drops (2.5 mg THC and 5 mg CBD) will be gradually augmented and adjusted individually to a maximum of 56 drops (20 mg THC and 40 mg CBD) per day, divided into two administrations. Placebo is an edible oil with the same color, smell, and flavor as medical cannabis oil given with the same dosage scheme.

Patients will take medical cannabis oil for 8 weeks, in addition to their usual treatments.

The study is divided into two 8-week periods. Participants will be randomized 1:1 between cannabinoids/placebo and placebo/ cannabinoids sequences and will receive the cannabis oil during one of these periods and the placebo during the other.

Participants will observe a wash-out week between the two study periods, and a final observation week without treatment intake is planned at the end of the second period.

Rating scales to evaluate the efficacy will be assessed before treatment, after 28 days, at the end of periods, and at the end of the study. Blood pressure will be evaluated daily. Vital signs, blood formula, and the reduction or discontinuation of other drugs will be recorded periodically. In addition, the health professionals' and relatives' appraisals will be recorded at five-time points.

A blood test at the beginning and the end of each period will allow the evaluation of the potential drug-drug interactions and the pharmacokinetics of cannabinoids. The cytochromes P450 (1A2, 2B6, 2C9, 2C19, 2D6, 3A4/5) enzymatic activity will be evaluated by phenotyping after Geneva micro-cocktail intake. The therapeutic drug monitoring will be measured at a steady-state characterizing the plasma through levels of THC, its two metabolites, 11-hydroxy-tetrahydrocannabinol and free carboxy-tetrahydrocannabinol, and CBD.

Inclusion criteria

• Patients with severe dementia from different origins (Alzheimer's disease, vascular, mixed)
• Clinical Dementia Rating ≥3
• Persisting behavior problems (Neuropsychiatric Inventory [NPI] score > 10) notwithstanding optimal conventional treatment
• SARS-CoV-2 recovered for two weeks, or SARS-CoV-2 fully vaccinated
• Consent obtained from the representative in the medical field according to art 378 Swiss Civil Code (SCC)

Exclusion criteria

• Severe organ deficiency such as cardiac, pulmonary, hepatic, renal insufficiency, or unstable heart rhythm
• Symptomatic orthostatic hypotension
• Major changes or instability of psychotropic medication in the week preceding the study enrolment
• Having taken THC and/or CBD in the 7 days before enrolment
• Hemoglobin < 10 g/dl
• Severe kidney failure defined by cockcroft calculation <30 ml/mn
• Alanine aminotransferase and aspartate aminotransferase > 3x upper limit of normal
• Any other medical conditions that would prevent participation in the whole study protocol.