Acute Cognitive Effects of the Dual Orexin Receptor Antagonist Lemborexant Compared With Suvorexant and Zolpidem in Recreational Sedative Users

The abuse potential of lemborexant, a dual orexin receptor antagonist, according to the 8 factors of the Controlled Substances Act

RATIONALE

Lemborexant (LEM) is a dual orexin receptor antagonist (DORA) approved in multiple countries including the USA, Japan, Canada, Australia, and several Asian countries for the treatment of insomnia in adults. As a compound with central nervous system activity, it is important to understand the abuse potential of LEM with respect to public health.

OBJECTIVES

This review discusses data for LEM relevant to each of the 8 factors of the United States Controlled Substances Act.

RESULTS

LEM did not demonstrate abuse potential in nonclinical testing and was associated with a low incidence of abuse-related adverse events in clinical study participants with insomnia disorder. Similar to other DORAs that have been evaluated (eg., almorexant, suvorexant (SUV), and daridorexant), LEM and the positive controls (zolpidem and SUV) also showed drug liking in a phase 1 abuse potential study that enrolled subjects who used sedatives recreationally. However, internet surveillance of SUV and the FDA Adverse Events Reporting System suggests that drugs in the DORA class display very low abuse-related risks in the community. Additionally, as described in FDA-approved labeling, it does not carry physical dependence and withdrawal risks.

CONCLUSIONS

LEM, similar to most other prescription insomnia medications, was placed into Schedule IV. However, LEM and other drugs in the DORA class may have a lower potential for abuse as suggested by real-world postmarketing data from federal surveys and internet surveillance, and thus may have lower risks to public health than Schedule IV benzodiazepines and nonbenzodiazepine hypnotics that potentiate GABA signaling.

UPLC-MS/MS Based Identification and Quantification of a Novel Dual Orexin Receptor Antagonist in Plasma Samples by Validated SWGTOX Guidelines

Lemborexant (LEM) is a novel dual orexin receptor antagonist (DORA), recently approved for the treatment of insomnia. As with other DORAs, LEM has potential of abuse and therefore placed in Schedule IV class by the United States Drug Enforcement Administration (USDEA). In this study, a sensitive and accurate UPLC-MS/MS assay was developed for the quantification of LEM in human plasma sample using losartan as an internal standard (IS). The chromatographic separation was performed by using gradient elution of mobile phase, comprising of 10 mM ammonium acetate and acetonitrile with a flow rate of 0.3 mL/min. An Acquity UPLC BEH C₁₈ (1.7 μm, 2.1 × 50 mm) column was used for separation of LEM and IS by maintaining the oven temperature of 40 °C. The electrospray ionization in positive mode was used for sample ionization. The precursor to product ion transition of 411.12 > 175.09 (qualifier) and 411.1 > 287.14 (quantifier) was used for detection and quantification of LEM, respectively, in multiple reaction monitoring mode. Being a drug of abuse, the assay was validated according to "Scientific Working Group for Toxicology" (SWGTOX) guidelines, including limit of detection (LOD), limit of quantification (LOQ), precision and bias, calibration model, interferences, carry-over effects, matrix effects, and stability parameters. The LOD and LOQ of the assay were 0.35 and 1.0 ng/mL, respectively. The linear range was between 1-300 ng/mL with correlation coefficient of ≥0.995. The method was also cross validated in rat plasma samples with acceptable ranges of precision and accuracy before its application for pharmacokinetic study in rats.

Suvorexant maintenance enhances the reinforcing but not subjective and physiological effects of intravenous cocaine in humans

Preclinical research has sought to understand the role of the orexin system in cocaine addiction given the connection between orexin producing cells in the lateral hypothalamus and brain limbic areas. Exogenous administration of orexin peptides increased cocaine self-administration whereas selective orexin-1 receptor antagonists reduced cocaine self-administration in non-human animals. The first clinically available orexin antagonist, suvorexant (a dual orexin-1 and orexin-2 receptor antagonist), attenuated motivation for cocaine and cocaine conditioned place preference, as well as cocaine-associated impulsive responding, in rodents. This study aimed to translate those preclinical findings and determine whether suvorexant maintenance altered the pharmacodynamic effects of cocaine in humans. Seven non-treatment seeking subjects with cocaine use disorder completed this within-subject human laboratory study, and a partial data set was obtained from one additional subject. Subjects were maintained for at least three days on 0, 5, 10 and 20 mg oral suvorexant administered at 2230 h daily in random order. Subjects completed experimental sessions in which cocaine self-administration of 0, 10 and 30 mg/70 kg of intravenous cocaine was evaluated on a concurrent progressive ratio drug versus money choice task. Subjective and physiological effects of cocaine were also determined. Cocaine functioned as a reinforcer and produced prototypic dose-related subjective and physiological effects (e.g., increased ratings of "Stimulated" and heart rate). Suvorexant (10, 20 mg) increased self-administration of 10 mg/70 kg cocaine and decreased oral temperature but did not significantly alter any other effects of cocaine. Future research may seek to evaluate the effects of orexin-1 selective antagonists in combination with cocaine.