Lamotrigine for Ketamine Dependence: A Randomized, Double-Blind, Placebo-Controlled Trial

Introduction

Ketamine is an anesthetic derivative of phencyclidine (PCP; 'Angel dust') with dissociative, analgesic and psychedelic properties. Recreational use of ketamine was first documented on the west coast of the United States in the early 1970s. Ketamine is frequently described as a "unique drug" because it shows hypnotic (sleep producing), analgesic (pain relieving) and amnesic (short-term memory loss) effects; no other drug used in clinical practice combines these three important features at the same time. Ketamine produces an anaesthetic state, which has been termed "dissociative anaesthesia", characterized by analgesia and changes in vigilance and perception, but it is not a sedative or hypnotic. It appears that ketamine selectively interrupts the thalamocortical system. Ketamine has some anxiolytic- and antidepressant-like properties in sub-anesthetic doses.

Mechanism of ketamine addiction

The existence of binding sites for PCP and ketamine were first identified in 1979. Earlier reports indicate that ketamine essentially blocks the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors. The antagonism of NMDA receptor is responsible for its specific properties including psychedelic, anesthetic, analgesic, anxiolytic, antidepressant, hypnotic effects and cognitive impairment. In fact, ketamine also binds to non-NMDA glutamate receptors and involves glutamate-independent mechanisms associated with nicotinic and muscarinic cholinergic, monoaminergic and opioid receptors.

Currently there is no specific pharmacological treatment model for ketamine dependence. Continuous urine screen plus medications for psychiatric symptoms treatment revealed fair results.