Wang Tongtong, Collet Jean-Paul, Shapiro Stan, Ware Mark A
Department of Epidemiology , McGill University, Montréal, Que.
CMAJ. 2008 Jun 17;178(13):1669-78. doi: 10.1503/cmaj.071178.
The therapeutic use of cannabis and cannabis-based medicines raises safety concerns for patients, clinicians, policy-makers, insurers, researchers and regulators. Although the efficacy of cannabinoids is being increasingly demonstrated in randomized controlled trials, most safety information comes from studies of recreational use.
We performed a systematic review of safety studies of medical cannabinoids published over the past 40 years to create an evidence base for cannabis-related adverse events and to facilitate future cannabis research initiatives. We critically evaluated the quality of published studies with a view to identifying ways to improve future studies.
A total of 321 articles were eligible for evaluation. After excluding those that focused on recreational cannabis use, we included 31 studies (23 randomized controlled trials and 8 observational studies) of medical cannabis use in our analysis. In the 23 randomized controlled trials, the median duration of cannabinoid exposure was 2 weeks (range 8 hours to 12 months). A total of 4779 adverse events were reported among participants assigned to the intervention. Most (4615 [96.6%]) were not serious. Of the 164 serious adverse events, the most common was relapse of multiple sclerosis (21 events [12.8%]), vomiting (16 events [9.8%]) and urinary tract infection (15 events [9.1%]). The rate of nonserious adverse events was higher among participants assigned to medical cannabinoids than among controls (rate ratio [RR] 1.86, 95% confidence interval [CI] 1.57-2.21); the rates of serious adverse events did not differ significantly between these 2 groups (RR 1.04, 95% CI 0.78-1.39). Dizziness was the most commonly reported nonserious adverse event (714 events [15.5%]) among people exposed to cannabinoids.
Short-term use of existing medical cannabinoids appeared to increase the risk of nonserious adverse events. The risks associated with long-term use were poorly characterized in published clinical trials and observational studies. High-quality trials of long-term exposure are required to further characterize safety issues related to the use of medical cannabinoids.
大麻及以大麻为基础的药物的治疗用途引发了患者、临床医生、政策制定者、保险公司、研究人员和监管机构对安全性的担忧。尽管大麻素的疗效在随机对照试验中得到越来越多的证实，但大多数安全信息来自娱乐性使用的研究。
我们对过去40年发表的医用大麻素安全性研究进行了系统综述，以建立与大麻相关不良事件的证据基础，并促进未来的大麻研究计划。我们严格评估了已发表研究的质量，以确定改进未来研究的方法。
共有321篇文章符合评估条件。在排除那些专注于娱乐性大麻使用的文章后，我们在分析中纳入了31项医用大麻使用的研究（23项随机对照试验和8项观察性研究）。在23项随机对照试验中，大麻素暴露的中位持续时间为2周（范围为8小时至12个月）。在分配到干预组的参与者中，共报告了4779起不良事件。大多数（4615起[96.6%]）不严重。在164起严重不良事件中，最常见的是多发性硬化症复发（21起事件[12.8%]）、呕吐（16起事件[9.8%]）和尿路感染（15起事件[9.1%]）。分配到医用大麻素组的参与者中不严重不良事件的发生率高于对照组（率比[RR]1.86，95%置信区间[CI]1.57 - 2.21）；这两组之间严重不良事件的发生率没有显著差异（RR 1.04，95%CI 0.78 - 1.39）。头晕是接触大麻素人群中最常报告的不严重不良事件（714起事件[15.5%]）。
短期使用现有的医用大麻素似乎会增加不严重不良事件的风险。已发表的临床试验和观察性研究对长期使用相关风险的描述不足。需要高质量的长期暴露试验来进一步明确与医用大麻素使用相关的安全问题。
