Ketamine by mouth - Preliminary review of the literature, including esketamine

Ketamine is an NMDA receptor antagonist, long used for its anesthetic and pain reducing properties, but has more recently demonstrated efficacy for treating depression. Evidence is also emerging for other psychiatric indications including posttraumatic stress disorder, anxiety disorders, obsessive compulsive disorder, and to support psychotherapy. In this context, there is greater demand for its use in various forms including intravenous, intramuscular, subcutaneous, intranasal, oral, and sublingual administration. While intravenous administration typically requires administration and monitoring in a healthcare setting, the safety precautions for other forms of ketamine are unclear. Limited data in this regard may elicit controversy among prescribers, who wish to improve patient access, and among regulatory bodies, who may impose limitations based on IV ketamine data. This project aims to bridge the gap between current literature and the clinical experience and opinions of ketamine prescribers. This information was obtained in the form of a survey and answered: “How do prescribers of ketamine, with emphasis on psychiatric care providers, find its safety profile and in what ways have they prescribed ketamine?” Information was gathered on prescriber profiles, indications for ketamine use, doses and routes of ketamine prescribed, side effects and adverse events, and prescribers’ opinions regarding monitoring requirements. Results were obtained from 45 providers with more than 1000 patient encounters over two countries. Non-IV forms of ketamine were commonly used, and the survey reported a favorable safety profile for ketamine. Non-IV Ketamine was reported to be safely utilized in a clinic setting with minimal monitoring and safety equipment, or at times, for home use. While survey results carry limitations, it appears that safety is dependent on dose and route, and strict universal regulations for all formulations may unnecessarily limit patient access.

In TRD outpatients treated in general hospitals, oral ketamine maybe better accepted and tolerated than iv ketamine. Conclusions about relative efficacy cannot be drawn because of the high dropout rate with iv ketamine.

A ketamine-containing tablet could be a convenient alternative to intravenous treatments, with fewer unpleasant side effects.