Location: University of California, San Francisco
Reporter: Jane Bonaventura
According to a recent study published in the journal Molecular Psychiatry, researchers from the University of California, San Francisco have discovered a significant divergence in the pharmacological and behavioral effects of ketamine enantiomers. The findings have important implications for understanding the abuse potential of this widely used anesthetic drug.
In previous research conducted in 1999, Hirota et al. investigated the stereoselective interaction of ketamine with opioid receptors. They found that ketamine exhibited preferential binding to mu, kappa, and delta opioid receptors. This suggests that the activation of these receptors may contribute to the reinforcing effects of (S)-ketamine, which is the more potent enantiomer.
Building on this earlier work, Levinstein et al. conducted a study to further explore the role of mu opioid receptor activation in mediating the reinforcing effects of (S)-ketamine. Using rats as their animal model, they demonstrated that mu opioid receptor activation was indeed responsible for the reinforcement observed with (S)-ketamine. These findings provide additional evidence for the abuse liability of this ketamine enantiomer.
In a separate study, Levinstein et al. investigated the binding properties of a novel radiotracer, 6-O-(2-[18F]fluoroethyl)-6-O-desmethyl-diprenorphine ([18F]FE-DPN), which specifically targets mu opioid receptors in vivo. The results of this study showed that [18F]FE-DPN preferentially binds to mu opioid receptors, indicating its potential as a valuable tool for studying the role of these receptors in opioid addiction and related disorders.
Expanding beyond the laboratory setting, Krupitsky et al. conducted a study on the use of ketamine-assisted psychotherapy in individuals with heroin dependence. They compared the outcomes of single versus repeated sessions of ketamine-assisted psychotherapy and found that multiple sessions yielded superior results in terms of reducing heroin use and improving overall well-being. This suggests that repeated exposure to ketamine in a therapeutic context may be particularly beneficial for individuals struggling with heroin addiction.
In a clinical case report, Hailozian et al. observed a synergistic effect when ketamine was combined with buprenorphine for the treatment of buprenorphine precipitated opioid withdrawal in a patient with fentanyl use. The combination of these two medications resulted in more successful management of withdrawal symptoms compared to buprenorphine alone. These findings highlight the potential of ketamine as an adjunctive therapy for opioid withdrawal.
Overall, these studies provide valuable insights into the pharmacological and behavioral aspects of ketamine, particularly its interaction with opioid receptors. The findings contribute to our understanding of the abuse liability of ketamine enantiomers and offer potential avenues for the development of new treatment approaches for opioid addiction. Further research in this area is warranted to fully elucidate the mechanisms underlying the effects of ketamine and its potential as a therapeutic tool.
