Over the last two decades the United States has experienced a significant increase in the medical and non-medical use of opioid drugs, resulting in record numbers of opioid-related overdoses and deaths. There was an initial increase in non-medical use of prescription opioids around 2002, followed later by increased heroin use and then most recently fentanyl. Inhalation is a common route of administration for opioids, with a documented history spanning back to Mediterranean antiquity and up through modern use with e-cigarette devices. Unfortunately, preclinical studies using inhalation as the route of administration remain relatively few. This study was conducted to determine the efficacy of e-cigarette vapor inhalation of heroin in rats. Non-contingent exposure to heroin or methadone vapor produced anti-nociceptive efficacy in male and female rats. Female rats were trained to self-administer heroin vapor; the most-preferring half of the distribution obtained more vapor reinforcers when the concentration of heroin was reduced in the vapor vehicle and when pre-treated with the opioid receptor antagonist naloxone. The anti-nociceptive effect of heroin self-administered by vapor was identical in magnitude to that produced by intravenous self-administration. Finally, anxiety-like behavior increased 24–48 h after last heroin vapor access, consistent with withdrawal signs observed after intravenous self-administration. In sum, these studies show that rewarding and anti-nociceptive effects of heroin are produced in rats by vapor inhalation using e-cigarette technology. Importantly, self-administration models by this route can be deployed to determine health effects of inhaled heroin or other opioids.

在过去的二十年里，美国阿片类药物的医疗和非医疗使用显着增加，导致阿片类药物过量和死亡人数创历史新高。2002 年左右，处方阿片类药物的非医疗使用最初增加，随后海洛因使用增加，最近是芬太尼。吸入是阿片类药物的常见给药途径，有记载的历史可以追溯到地中海古代，直到现代使用电子烟设备。不幸的是，使用吸入作为给药途径的临床前研究仍然相对较少。本研究旨在确定电子烟蒸气吸入海洛因对大鼠的疗效。海洛因或美沙酮蒸气的非偶然暴露在雄性和雌性大鼠中产生抗伤害作用。雌性老鼠接受过自我注射海洛因蒸气的训练；当蒸气载体中海洛因的浓度降低并且用阿片受体拮抗剂纳洛酮预处理时，最优选的一半分布获得了更多的蒸气增强剂。通过蒸气自我给药的海洛因的抗伤害感受作用在幅度上与静脉内自我给药产生的相同。最后，在最后一次使用海洛因蒸气后 24-48 小时，焦虑样行为增加，这与静脉自我给药后观察到的戒断迹象一致。总之，这些研究表明，使用电子烟技术通过蒸气吸入在大鼠中产生海洛因的奖励和抗伤害作用。重要的，