Off-label use of transmucosal ketamine as a rapid-acting antidepressant: a retrospective chart review

Objective: This study evaluated the effectiveness and safety of subanesthetic doses of ketamine using an off-label, transmucosal administration route in patients with treatment-resistant depression. Methods: A retrospective chart review was conducted to identify patients who met the inclusion criteria for treatment-resistant major depressive disorder. Seventeen such patients who received subanesthetic doses of ketamine were included. Patient demographics, efficacy (drug refill, clinician notes), side effects, and concurrent medications were assessed. Results: Benefit from low-dose transmucosal ketamine was noted in 76% of subjects (average age 48 years, 88% female), with a dose duration lasting 7-14 days. No notable side effects were noted. The most common classes of concurrent medications to which ketamine was added were serotonin-norepinephrine reuptake inhibitors (59%), stimulants (47%), folate replacement (47%), and benzodiazepines (47%). Conclusion: Our results provide preliminary evidence of the effectiveness and safety of lowdose transmucosal ketamine in treatment-resistant patients. A controlled, prospective pilot study is warranted to validate these findings.