Real-world data from the German Pain E-registry
While there are some signs that opioid overdoses in the US are beginning to decrease, this is no consolation to those whose loved ones lost their lives due to addiction. To end this public health crisis and safely treat people with chronic pain, there is an urgent need to develop novel therapies with a lower risk of dependence.
Evidence has shown that cannabis is a powerful analgesic that effectively reduces pain.  In fact, the majority of US states with medical cannabis programs include chronic pain as an indication for treatment. But Americans are not alone in their recognition of medical cannabis for pain treatment.
In March 2017, Germany legalized the use of medical cannabis with the Act Amending Narcotics and Other Regulations.  Since then, the medical cannabis industry has grown exponentially. In the first half of this year, Germany imported nearly 2,500 kg of cannabis. As physicians become more comfortable prescribing cannabis, however, they require additional data on its safety and efficacy, prompting a study recently published by German researchers. 
Ueberall et al. (2019) evaluated open-label data from the German Pain E-registry in adults with severe chronic pain who used Sativex®, an oromucosal cannabis spray.  These data were analyzed to assess the safety and efficacy of this cannabis formulation using real-world outcomes.
Sativex is approved in the EU for the treatment of spasticity due to multiple sclerosis and is manufactured by GW Pharma, which recently was awarded FDA approval for Epidiolex (prescription cannabidiol, CBD) to treat severe forms of pediatric epilepsy. While Sativex is not currently available in the US, GW Pharma is planning to file for approval.
Since this study was retrospective, data were analyzed from people who started Sativex treatment between March 10 and December 31, 2017, as part of routine care along with other medications for 12 weeks. Safety and efficacy assessments were measured based on survey responses. 
One spray of Sativex provides a 100-µl dose of 2.7 mg tetrahydrocannabinol (THC) and 2.5 mg CBD, a near 1-to-1 ratio. While dosages varied according to physician recommendations, patients used approximately 7 doses per day by week 9 of treatment. 
Eight hundred patients were included in the analyses, and the majority were female Caucasians in their mid-40s who had been experiencing pain for over one year. 
Within the first week of treatment, self-reported pain intensity differed significantly across lowest-, average-, and highest-rated pain scores. Those with neuropathic pain and high baseline pain scores responded with the greatest overall improvement. Additionally, there were significant improvements in measures related to quality of life compared to the baseline (before treatment was started). 
While Sativex was well tolerated, nearly 20% of patients experienced an adverse event, the most common being disruption of taste, mouth discomfort, and application-related pain.  These effects are likely due to oral delivery.
Based on these real-world results, Sativex appears to have a favorable efficacy and safety profile in people with severe chronic pain. However, it’s important to note the limitations of this study. Due to its retrospective nature, there was no control group including those who did not take Sativex; thus, comparisons could only be made before and after treatment in the same group and not between groups. Since it was not a clinical trial, other variables could not be controlled for. 
Still, the encouraging findings indicate that Sativex or other cannabis formulations may be used to effectively and safely treat chronic pain instead of opioids that carry a high risk of dependence and addiction.
- Hill, K.P., “Medical Marijuana for Treatment of Chronic Pain and Other Medical and Psychiatric Problems: A Clinical Review.” JAMA, vol.313, no. 24, 2015, pp. 2474-2483 (impact factor: 51.273; cited by: 312)
- Ueberall, M.A., et al. “Effectiveness and Tolerability of THC:CBD Oromucosal Spray As Add-on Measure In Patients With Severe Chronic Pain: Analysis of 12-Week Open-label Real-world Data Provided By The German Pain e-Registry.” J Pain Res. vol.12, 2019, pp. 1577-1604 (impact factor: 2.581; cited by: N/A)