Routes of abuse of prescription opioid analgesics: a review and assessment of the potential impact of abuse-deterrent formulations

Compulsive-Like Sufentanil Vapor Self-Administration in Rats

Opioid misuse is at historically high levels in the United States, with inhalation (ie, smoking and vaping) being one of the most common routes of consumption. We developed and validated a novel preclinical model of opioid self-administration by inhalation that does not require surgery and reliably produces somatic and motivational signs of dependence. Rats were trained to perform an operant response (nosepoke) to receive 10 s of vaporized sufentanil, a potent opioid, in 2 h daily sessions. Rats readily and concentration-dependently self-administered vaporized sufentanil. Rats exhibited a significant increase in responding for sufentanil when given the preferential μ-opioid receptor inverse agonist naloxone, suggesting the participation of μ-opioid receptors in the reinforcing properties of sufentanil vapor. Serum sufentanil concentrations significantly correlated with the number of sufentanil vapor deliveries. Rats that were given long access (LgA; 12 h/day) but not short access (ShA; 1 h/day) to vaporized sufentanil escalated their drug intake over time and exhibited both naloxone-precipitated somatic signs of opioid withdrawal and spontaneous withdrawal-induced mechanical hypersensitivity. After 6 months of forced drug abstinence, LgA rats returned to pre-escalation baseline levels of responding for sufentanil and mechanical sensitivity. Upon subsequent re-escalation (ie, after the return to extended access to sufentanil vapor), LgA rats again developed naloxone-precipitated somatic signs of withdrawal and spontaneous withdrawal-induced mechanical hypersensitivity. These findings demonstrate that the operant sufentanil vapor self-administration model has both face and construct validity and therefore will be useful for investigating the neurobiological basis of opioid addiction.

Patterns of abuse and routes of administration for immediate-release hydrocodone combination products

PURPOSE

Prescriptions for hydrocodone immediate-release (IR) combination products have recently decreased, yet they represent the majority of opioid prescriptions dispensed and are commonly abused analgesics among both adults and adolescents. Little data exist to understand the contribution of IR products to the problem of prescription opioid abuse. This study aimed to better understand abuse patterns for hydrocodone IR combination products among adult and adolescent substance abusers.

METHODS

This cross-sectional study examines abuse prevalence (including abuse adjusted for prescription volume and morphine milligram equivalents) and abuse characteristics for hydrocodone IR combination products and other prescription opioids among separate samples of adults and adolescents assessed for substance abuse problems or entering treatment from January 2012 through June 2015.

RESULTS

Results indicate higher abuse for hydrocodone IR combination products than other opioid categories per 100 assessments but lower per prescriptions dispensed. Hydrocodone IR combination products had similar abuse prevalence to all extended-release and long-acting opioids when considering abuse measured per morphine milligram equivalents dispensed. An upward trend in hydrocodone IR combination product abuse was observed among adult substance abusers comparing the period prior to and after Drug Enforcement Administration rescheduling of these products in October 2014. Most individuals reported oral abuse of hydrocodone IR combination products, but snorting, reported by 23% of hydrocodone IR combination product abusers, also appears to be a route of abuse that may have public health relevance.

CONCLUSIONS

Given their high prescription volume, hydrocodone IR combination products, even at a relatively low prevalence of abuse, may contribute substantially to the overall problem of prescription opioid abuse. Additional public health interventions, including development of abuse-deterrent formulations for these types of opioid products may aid in reducing their abuse.

Prevalence of Use of Electronic Nicotine Delivery Systems (ENDS) to Vape Recreational Drugs by Club Patrons in South London

INTRODUCTION

Electronic nicotine delivery systems (ENDS, often called e-cigarettes) are nicotine delivery devices that heat nicotine into vapour that is inhaled, a process called 'vaping'. Use eclipsed nicotine-replacement therapy (NRT) in 2014 but ENDS role in smoking cessation remains controversial. Safety has not been proven and there have been reports to US poison centres regarding potential ENDS-related nicotine toxicity. A further concern is use of ENDS to vape recreational drugs, but there is limited data to substantiate this. The aim of this study was to report on ENDS use to vape recreational drugs in patrons of a South London nightclub where high prevalence of recreational drug use has previously been shown.

METHODS

A convenience sample of 101 participants was surveyed in March 2015 as part of a larger survey on drug use. Individuals were asked if they used ENDS to vape nicotine and/or other substances (and if so which substances).

RESULTS

Ninety (89.1 %) of respondents were male with median age of 28 years (IQR 23-34). Eighty (79.2 %) currently smoked cigarettes; 20 (19.8 %) currently used ENDS for nicotine. Six (5.9 %) reported using ENDS to take other substances: 2 for 'liquid cannabis' and 4 did not elaborate on the substance(s) used. Of these 6, 3 were using ENDS to vape nicotine and 3 had never used them for nicotine.

CONCLUSION

5.9 % of individuals in this sample reported using ENDS to vape substances other than nicotine. Further work is required in larger populations to determine how common this is, evaluate which agents are being vaped and to inform appropriate public education.

New Chronic Pain Treatments in the Outpatient Setting: Review Article

Chronic pain is an issue encountered by many health care providers in their routine clinical practice. In addition to generalized patient suffering, this condition has significant clinical, psychological, and socioeconomic impact due to its widespread occurrence. The landscape of chronic pain management has been changing rapidly with an array of treatment innovations, better understanding of established therapies, and care coordination across specialties. In this article, we have reviewed emerging new modalities as well as transformation of established therapies by interventional, pharmacologic, rehabilitative, psychological, complimentary, and interdisciplinary approaches.

Abuse-deterrent formulations of prescription opioid analgesics in the management of chronic noncancer pain

Misuse, abuse and diversion of prescription opioid analgesics represent a global public health concern. The development of abuse-deterrent formulations (ADFs) of prescription opioid analgesics is an important step toward reducing abuse and diversion of these medications, as well as potentially limiting medical consequences when misused or administered in error. ADFs aim to hinder extraction of the active ingredient, prevent administration through alternative routes and/or make abuse of the manipulated product less attractive, less rewarding or aversive. However, opioid ADFs may still be abused via the intended route of administration by increasing the dose and/or dosing frequency. The science of abuse deterrence and the regulatory landscape are still relatively new and evolving. This paper reviews the current status of opioid ADFs, with particular focus on different approaches that can be used to deter abuse, regulatory considerations and implications for clinical management.