Neuroendocrine effects of naltrexone versus nalmefene in humans.

OBJECTIVE: Naltrexone and nalmefene are approved for the treatment of alcohol use disorders, in different countries. Naltrexone is also approved for the treatment for opioid use disorders, most recently in a depot formulation. These compounds target primarily µ(mu)- and κ(kappa)-opioid receptor systems, which are involved in the downstream neurobiological effects of alcohol and in the modulation of neuroendocrine stress systems. The study objective was to compare the neuroendocrine effects of naltrexone and nalmefene on adrenocorticotropic hormone (ACTH), cortisol, and prolactin, in normal volunteers. METHOD: Adult normal volunteers (n = 11 male and n = 9 female) were studied in a stress-minimized inpatient setting on three consecutive days, after intravenous saline, naltrexone HCl (10 mg), or nalmefene HCl (10 mg), in fixed order. ACTH, cortisol, and prolactin were analyzed pre-injection and up to 180 min post-injection. RESULTS: Naltrexone and nalmefene caused elevations in ACTH and cortisol compared with saline. Nalmefene had a greater effect on ACTH and cortisol, compared with naltrexone. Both compounds also caused elevations in prolactin in males (females were not examined, due to the influence of menstrual cycle on prolactin). CONCLUSIONS: This study suggests that both nalmefene and naltrexone have effects potentially due to κ-partial agonism in humans, as well as antagonist effects at µ-receptors.

Are trait impulsivity and exposure to cannabis or alcohol associated with the age of trajectory of cocaine use? A gender-specific dimensional analysis in humans with cocaine dependence diagnosis.

Cocaine use disorders (CUD) cause major morbidity and optimized prevention efforts are critical. It is unclear if trait impulsivity and exposure to cannabis or alcohol are associated with age trajectory of cocaine use (e.g., age of onset of heaviest use, or time of escalation), or with vulnerability to develop a CUD. This is an observational study with volunteers (≥ 18 years old), from a metropolitan area. The sample (n = 1,010) included: n = 360 normal volunteers, n = 438 with cocaine dependence (CD) diagnoses, and n = 212 with other addictive diseases. Trait impulsivity was examined with BIS-11 scores. Maximal self-exposure to cannabis, alcohol, and cocaine were characterized dimensionally with Kreek-McHugh-Schluger-Kellogg (KMSK) scales. Time of escalation was defined as the interval between age of first use and age of onset of heaviest use. Onset of maximal use of cannabis (median age = 17) and alcohol (median age = 21) preceded that of cocaine (median age = 27), in volunteers with CD. Multivariate Cox regressions in volunteers with CD show that increasing self-exposure to cannabis was a predictor of earlier onset of heaviest use of cocaine. Also, more rapid time of escalation of alcohol was a predictor of more rapid time of escalation of cocaine. A multiple logistic regression shows that increasing self-exposure to cannabis or alcohol was a positive predictor of odds of CD diagnosis. Trait impulsivity and gender were not significant predictors in these multivariate analyses. This study shows that aspects of adolescent exposure to nonmedical cannabis and alcohol are predictors of early onset of CUD, and may be potentially targeted for prevention efforts. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Repeated Administration of Opra Kappa (LY2456302), a Novel, Short-Acting, Selective KOP-r Antagonist, in Persons with and without Cocaine Dependence.

The κ-opioid receptor (KOP-r) system and its endogenous ligands, the dynorphins, are involved in the neurobiological regulation of addictive states, and of mood. There are limited data on the impact of selective KOP-r antagonism in humans on basic biobehavioral functions, or on addictive diseases and mood disorders. Previously studied selective KOP-r antagonists have unusual pharmacodynamic and pharmacokinetic properties (slow development of KOP-r selectivity, extremely long duration of action) that limit translation to human studies. A recently developed selective KOP-r-antagonist, Opra Kappa (LY2456302; CERC-501), has medication-like duration of action, oral bioavailability, and target engagement. The current study is the first investigation of the effects of a KOP-r-antagonist in cocaine-dependent persons in comparison with normal volunteers. In a stress-minimized inpatient setting, we determined the neuroendocrine and neurobehavioral effects of repeated administration of an active dose of Opra Kappa (10 mg p.o. daily, four consecutive days in comparison with an initial baseline day). Healthy volunteers (n=40), persons diagnosed with cocaine dependence in early abstinence (<2 months, EACD) (n=23), and drug-free former cocaine-dependent persons (7-month to 25-year abstinence, DFFCD) (n=7) were studied, with measurements including circulating neuroendocrine hormones, affect, and, in cocaine-dependent persons, cocaine craving. Modest adverse events related to Opra Kappa included pruritus, observed in a subset of individuals. No significant change was observed in serum prolactin levels following Opra Kappa administration, but modest increases in circulating adrenocorticotropic hormone and cortisol were observed. No significant changes were noted in measures of depression or cocaine craving in this stress-minimized setting. Overall, these studies demonstrate that effects of 10 mg Opra Kappa are largely consistent with those predicted for a selective KOP-r antagonist. This medication regimen was tolerable, and is therefore feasible for further studies in cocaine-dependent persons.

Repeated Administration of Opra Kappa (LY2456302), a Novel, Short-Acting, Selective KOP-r Antagonist, in Persons with and without Cocaine Dependence.

This corrects the article DOI: 10.1038/npp.2017.205.

Re-evaluation of the KMSK scales, rapid dimensional measures of self-exposure to specific drugs: Gender-specific features.

BACKGROUND: The Kreek-McHugh-Schluger-Kellogg (KMSK) scales provide a rapid assessment of maximal self-exposure to specific drugs and can be used as a dimensional instrument. This study provides a re-evaluation of the KMSK scales for cannabis, alcohol, cocaine, and heroin in a relatively large multi-ethnic cohort, and also the first systematic comparison of gender-specific profiles of drug exposure with this scale. METHODS: This was an observational study of n = 1,133 consecutively ascertained adult volunteers. The main instruments used were the SCID-I interview (DSM-IV criteria) and KMSK scales for cannabis, alcohol, cocaine, and heroin. RESULTS: Participants were 852 volunteers (297 female) with specific DSM-IV abuse or dependence diagnoses, and 281 volunteers without any drug diagnoses (154 female). Receiver operating characteristic (ROC) curves were calculated for concurrent validity of KMSK scores with the respective DSM-IV dependence diagnoses. The areas under the ROC curves for men and women combined were 99.5% for heroin, 97% for cocaine, 93% for alcohol, and 85% for cannabis. Newly determined optimal KMSK "cutpoint" scores were identical for men and women for cocaine and heroin dependence diagnoses, but were higher in men than in women, for cannabis and alcohol dependence diagnoses. CONCLUSIONS: This study confirms the scales' effectiveness in performing rapid dimensional analyses for cannabis, alcohol, cocaine, and heroin exposure, in a cohort larger than previously reported, with "cutpoints" changed from initial determinations, based on this larger sample. The KMSK scales also detected gender differences in self-exposure to alcohol and cannabis that are associated with the respective dependence diagnoses.