Cannabis for the Treatment of Chronic Pain in the Era of an Opioid Epidemic: A Symposium-Based Review of Sociomedical Science.

OBJECTIVE: This manuscript reviews medical literature published pertaining to the management of chronic pain with medical marijuana therapy (MMJ), with an emphasis on the social, medical, and legal aspects of therapy. DESIGN: Narrative review of peer-reviewed literature. METHODS: The 3rd Symposium on Controlled Substances and Their Alternatives for the Treatment of Pain was held in Boston on February 27, 2016, with a focus on MMJ for the treatment of chronic pain. Invited speakers had diverse backgrounds, including pain management, addiction psychiatry, neurology, and legal authorities. The purpose of this conference and this subsequent narrative review is to provide a medical, legal, and logistical framework for physicians and other health care providers to refer to when considering the initiation of medical marijuana therapy. RESULTS: The invited speakers each covered a unique aspect of MMJ therapy for the treatment of chronic pain. These presentations highlighted the current data for and against the use of MMJ as a pain therapy. Optimal patient selection and screening, in addition to policy developments, were discussed. CONCLUSIONS: Increasing interest in MMJ for chronic pain underscores a need for primary care and pain physicians to better understand the indications and evidence for its use free from cultural bias. Given a lack of full conclusive clinical utility, continued research is needed to better understand how to best utilize MMJ therapy for the treatment of chronic pain. Policy initiatives, such as enumerated indications, should follow medical science in order to prevent another abused substance epidemic.

The Association Between Cannabis Use and Aberrant Behaviors During Chronic Opioid Therapy for Chronic Pain.

Objective: Health care providers are likely to see an increase in the concomitant use of cannabis and opioids, particularly with the increased liberalization and ongoing research into the possible role of medical marijuana for chronic pain. Recent literature reports a prevalence of concurrent use ranging from 8.9% to 31.8%. The primary aim of this study was to determine the relationship between cannabis use and aberrant drug behaviors in noncancer pain patients receiving chronic opioid therapy. Design: Retrospective chart review. Setting: Community-based, interdisciplinary pain management center. Subjects: Data from 209 patients who were evaluated for a medication management program between October 1, 2011, and January 1, 2014, and met inclusion criteria. Forty-four were positive for cannabis in their initial random urine drug toxicology. Methods: Data from electronic health records, including demographics, urine drug toxicology, disability, opioid dose, opioid risk assessment data, and pain severity were analyzed to examine differences among cannabis users and noncannabis users. Results: Subjects with cannabis in their initial urine drug toxicology were more likely to have a future occurrence of an opioid-related aberrancy (P < 0.001), be male (P = 0.047), have a history of substance abuse (P = 0.013), and be enrolled into a higher level of clinical monitoring of opioid medication use (P = 0.008). No other associations with demographic and clinical variables reached statistical significance. Conclusions: Concurrent use of cannabis and opioids by patients with chronic pain appears to indicate higher risk for opioid misuse. Closer monitoring for opioid-related aberrancy is indicated for this group of patients.

Galanin knockout mice show disturbances in ethanol consumption and expression of hypothalamic peptides that stimulate ethanol intake.

BACKGROUND: There is growing evidence suggesting that hypothalamic galanin (GAL), which is known to stimulate intake of a fat-rich diet, has a role in promoting the consumption of ethanol. The present study further examined this possibility in GAL knockout (GALKO) mice. METHODS: Two groups of female and male GALKO mice, compared to wild-type (WT) controls, were trained to voluntarily drink increasing concentrations of ethanol, while maintained on lab chow and water. They were examined in terms of their daily ethanol intake and preference, acute consumption of a high-fat diet, preference for flavored solutions, and expression of different peptides shown to stimulate ethanol intake. RESULTS: In the GALKO mice compared to WT, the results revealed: (i) a 35 to 45% decrease in ethanol intake and preference, which was evident only at the highest (15%) ethanol concentration, was stronger in female than in male mice, and was seen with comparisons to littermate as well as nonlittermate WT mice; (ii) a 48% decrease in acute intake of a fat-rich diet, again stronger in female than male mice; (iii) no difference in consumption of sucrose or quinine solutions in preference tests; (iv) a total loss of GAL mRNA in the hypothalamic paraventricular nucleus (PVN) of female and male mice; and (v) a gender-specific change in mRNA levels of peptides in the perifornical lateral hypothalamus (PFLH), orexin and melanin-concentrating hormone, which are known to stimulate ethanol and food intake and were markedly decreased in females while increased in males. CONCLUSIONS: These results provide strong support for a physiological role of PVN GAL in stimulating the consumption of ethanol, as well as a fat-rich diet. Ablation of the GAL gene produced a behavioral phenotype, particularly in females, which may reflect the functional relationship of galanin to ovarian steroids. It also altered the peptides in the PFLH, with their reduced expression contributing to the larger behavioral effects observed in females and their increased expression attenuating these effects in males.