British Columbia Centre on Substance Use, Vancouver, British Columbia, Canada.
School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada.
PLoS Med. 2019 Nov 19;16(11):e1002967. doi: 10.1371/journal.pmed.1002967. eCollection 2019 Nov.
Ecological research suggests that increased access to cannabis may facilitate reductions in opioid use and harms, and medical cannabis patients describe the substitution of opioids with cannabis for pain management. However, there is a lack of research using individual-level data to explore this question. We aimed to investigate the longitudinal association between frequency of cannabis use and illicit opioid use among people who use drugs (PWUD) experiencing chronic pain.
This study included data from people in 2 prospective cohorts of PWUD in Vancouver, Canada, who reported major or persistent pain from June 1, 2014, to December 1, 2017 (n = 1,152). We used descriptive statistics to examine reasons for cannabis use and a multivariable generalized linear mixed-effects model to estimate the relationship between daily (once or more per day) cannabis use and daily illicit opioid use. There were 424 (36.8%) women in the study, and the median age at baseline was 49.3 years (IQR 42.3-54.9). In total, 455 (40%) reported daily illicit opioid use, and 410 (36%) reported daily cannabis use during at least one 6-month follow-up period. The most commonly reported therapeutic reasons for cannabis use were pain (36%), sleep (35%), stress (31%), and nausea (30%). After adjusting for demographic characteristics, substance use, and health-related factors, daily cannabis use was associated with significantly lower odds of daily illicit opioid use (adjusted odds ratio 0.50, 95% CI 0.34-0.74, p < 0.001). Limitations of the study included self-reported measures of substance use and chronic pain, and a lack of data for cannabis preparations, dosages, and modes of administration.
We observed an independent negative association between frequent cannabis use and frequent illicit opioid use among PWUD with chronic pain. These findings provide longitudinal observational evidence that cannabis may serve as an adjunct to or substitute for illicit opioid use among PWUD with chronic pain.
生态研究表明，增加大麻的可及性可能有助于减少阿片类药物的使用和危害，而且医用大麻患者描述了用大麻替代阿片类药物来进行疼痛管理。然而，目前缺乏使用个体层面数据来探讨这一问题的研究。我们旨在调查慢性疼痛患者中，大麻使用频率与非法阿片类药物使用之间的纵向关联。
本研究纳入了 2014 年 6 月 1 日至 2017 年 12 月 1 日期间，加拿大温哥华 2 个前瞻性药物使用人群队列中报告有主要或持续性疼痛的患者（n=1152）的数据。我们使用描述性统计方法来检查大麻使用的原因，并使用多变量广义线性混合效应模型来估计每日（每天一次或以上）大麻使用与每日非法阿片类药物使用之间的关系。研究中有 424 名（36.8%）女性，基线时的中位年龄为 49.3 岁（IQR 42.3-54.9）。总共有 455 名（40%）报告每日非法阿片类药物使用，410 名（36%）在至少一个 6 个月随访期内报告每日大麻使用。大麻使用的最常见治疗原因是疼痛（36%）、睡眠（35%）、压力（31%）和恶心（30%）。调整人口统计学特征、物质使用和与健康相关的因素后，每日大麻使用与每日非法阿片类药物使用的可能性显著降低相关（调整后的比值比 0.50，95%CI 0.34-0.74，p<0.001）。研究的局限性包括物质使用和慢性疼痛的自我报告测量，以及缺乏关于大麻制剂、剂量和给药方式的数据。
我们观察到，慢性疼痛患者中，频繁大麻使用与频繁非法阿片类药物使用之间存在独立的负相关。这些发现提供了纵向观察证据，表明大麻可能作为慢性疼痛患者中非法阿片类药物使用的辅助或替代药物。
