Oral and Sublingual Ketamine

Major Depressive Disorder (MDD) is one of the most common and severe mental illnesses in the world. Ketamine treatment, especially intravenous ketamine (IVK) and intranasal esketamine (INE), is becoming more popular and is being used more. But these ways of administering aren't perfect. They mostly have problems with cost, accessibility, and the issues of administering. The oral and sublingual routes of ketamine are cheaper alternatives, but they haven't been looked into as much in the medical and academic circles. This is a small pilot feasibility study, involving ten patient participants who will be randomly assigned to take ketamine by oral and sublingual routes as part of a single-blind, crossover design. A local London pharmacy-Ultimate Care Compounding will provide the ketamine formulations.

Ten patients between 18 and 65 years old with Major Depressive Disorder will be recruited from the Mental Health Care Programs at LHSC, Victoria Hospital and SJHC, Parkwood Institute, (that has treatment resistant depression treatment focus). After a screening baseline visit, which will include clinical interviews with medication reconciliation, psychiatric evaluations, routine standard laboratory tests, and an electrocardiogram (ECG).

Due to capacity limitations at the Centre for Clinical Investigation and Therapeutics (CCIT), a maximum of 5 participants will undergo pharmacokinetic sampling simultaneously, enrolment will proceed in two sequential groups with treatment order assigned by group. Group A (n=5): The first 5 eligible participants will receive oral ketamine in Treatment Period 1 and sublingual ketamine in Treatment Period 2. Group B (n=5): The next 5 eligible participants will receive sublingual ketamine in Treatment Period 1 and oral ketamine in Treatment Period 2. Recruitment for Group B will commence once Group A has completed the clinical intervention phase.

During Monday and Thursday of each of Weeks 1 and 2, Group A will receive oral ketamine, while Group B will receive sublingual ketamine. Weeks 3 and 4 are a washout period. In Weeks 5 and 6, on Mondays and Thursdays, groups will switch to the other form of administration \[See flowchart of study procedure\]. Weeks 7 and 8 are washout periods to ensure consistency with the first half of the study and provide a similar framework for clinical assessments. Blood samples will be collected at 2 time points at the Center for Clinical Investigation and Therapeutics at University Hospital. The study goal is to help define safe and effective oral/SL ketamine doses based on Pharmacokinetic profiles.