New studies from the UK Registry point to the fact that various formulations may improve patients’ quality of life
Chronic pain is a condition that has significant negative effects in terms of quality of life and impact on daily activities and work, as well as on public health.
Although the data supporting efficacy are limited, pharmacological therapies are the most widespread treatment option, but there is growing interest in the possible role of different strategies in chronic pain management.
In this context, cannabis-based medicines provide a promising therapeutic option, thanks to their ability to reduce nociceptive signals in the central and peripheral nervous system and their role in modulating the mechanisms involved in pain sensations in the somatosensory cortex and in the limbic system.
However, the studies conducted so far have had mixed results, depending on the product used, the type of chronic pain evaluated and the observation period.
An important source of data to evaluate the efficacy of cannabis-based medicines is the UK Medical Cannabis Registry (UKMCR), which since 2019 has been collecting clinical data on patients who are prescribed these products in the United Kingdom, with the aim to evaluate their therapeutic benefits in different clinical conditions.
More solid evidence from new studies
Various analyses were conducted on the registry data, aimed at evaluating the efficacy and safety of cannabis-based preparations for medical use in the treatment of chronic pain.
A recently published work evaluated changes in general health-related quality of life (HRQoL), the specific outcomes of chronic pain and adverse events in a cohort of patients treated only with cannabis-based products (oils and/or dried flos) [1].
761 patients were enrolled in the prospective cohort study, 348 of whom (45.7%) took the oil formulation, 36 (4.7%) the dried flos and the other 377 (49.5%) both forms. The average age was 47. Of the participants, 326 (42.8%) were cannabis users, 122 (16%) had used it in the past and the remaining 313 (41.1%) had never used it.
To evaluate the efficacy of treatment with cannabis-based preparations on the quality of life of patients with chronic pain, participants completed various questionnaires aimed at estimating the change in patient-reported outcome measures (PROMs) after 1, 3 and 6 months from the start of treatment compared to baseline.
In the group treated with the oil formulation and in the one that used both forms, statistically significant improvements were observed, compared to baseline, at 1, 3 and 6 months in measures relating to pain, sleep and quality of life related to general health. Furthermore, in the group that took the oil-flos combination therapy, significant improvements were also recorded with regard to specific patient-reported outcomes for anxiety, at all time points.
A reduction in opioid prescriptions was also observed after 6 months of treatment compared to baseline, with a 3.28% decrease in the average dose.
With regards to safety, the most common adverse events were fatigue (114 cases, 14%), drowsiness (88 cases, 10.8%) and dry mouth (84 cases, 10.3%), all mild-moderate, with a higher likelihood related to females and to non-users or former cannabis users.
The results of the study confirm the evidence collected by a previous analysis conducted on a series of cases from the UK Medical Cannabis Registry, which had involved 110 patients treated with oil formulations for chronic pain [2]. Also in this case the treatment was associated with improvements in the specific outcomes of pain, health-related quality of life and sleep quality, with positive safety data.
How to read the results
“These results suggest that both oil and flos-based formulations are associated with an improvement in long-term quality of life in patients with chronic pain, and do not involve adverse or disabling events,” the authors of the study commented. “The higher incidence of adverse events observed in females, previously cannabis-naïve users, and ex-cannabis users is an aspect to be taken into account in future studies and when prescribing cannabis-based medicines”.
Reference
- Tait J, Erridge S, Holvey C, et al. Clinical outcome data of chronic pain patients treated with cannabis-based oils and dried flower from the UK Medical Cannabis Registry. Expert Rev Neurother. 2023 Apr;23(4):413-23.
- Kawka M, Erridge S, Holvey C, et al. Clinical outcome data of first cohort of chronic pain patients treated with cannabis-based sublingual oils in the United Kingdom: analysis from the UK Medical Cannabis Registry. J Clin Pharmacol. 2021 Dec;61(12):1545-54.
