Three observational studies from Australia and Germany have shown that orally administered plant-derived and synthetically produced THC have provided patients with positive outcomes for what was previously considered to be treatment-resistant pain, also known as refractory or intractable pain.
In a study from Australia, researchers wished to address what they considered to be a lack of sufficient safety and efficacy data for medicinal cannabis. They designed an observational study to record effectiveness, adverse events (AEs), and health-related quality of life (HRQoL) scores in patients suffering from treatment-resistant pain. All the patients in the study were prescribed an oral medicinal cannabis oil formulation containing an equal THC CBD ratio at a private cannabis clinic.
The results of the study show pain scores in patients were significantly reduced, with all patients reporting a lower pain score. No serious AEs were reported by any of the patients in the study, although more than half of the patients reported at least one instance of AE. Reported AEs were numerous and included drowsiness, anxiety, insomnia, dry mouth, balance problems, dry eyes, increased blood pressure, skin irritation and more. However nearly half (49%) of the cohort reported improvements to their sleep and over a third (36%) reported less fatigue.
The study concluded that more than one third of the participants benefitted from the medicinal cannabis oil treatment, which researchers considered to be significant as they all suffered from previously untreatable pain.
In a second study from Germany, researchers wanted to contrast the effectiveness and tolerability of a plant-derived cannabis product against a synthetic THC based product, as an additional medicine in patients with severe neuropathic pain which had previously been ‘poorly controlled’. They conducted an observational analysis study of anonymous real-world data collected from patients who had been treated with either the plant-derived THC containing spray nabiximols or the synthetic cannabis oral medication dronabinol.
The researchers found that patients using dronabinol, and the patients using nabiximols had reported a ‘significantly improved’ pain score, and many had reported a reduction in the use of their pain medication. Although they did, however, note that the patients that used dronabinol were more likely to discontinue use, citing AE as the reason.
Their conclusion states “Treatment with cannabinoids appears to be an effective alternative option for patients with severe neuropathic pain that is poorly responsive to established treatments.”
The third study was similar to the second in that it tested the efficacy of the synthetic THC based medicine dronabinol as an additional treatment, but this time in patients with treatment-resistant pain. Researchers observed the data from 11456 patients who had been administered dronabinol for a 12 week period.
They found that patients reported a pain reduction score of 50%, an increase in activities of daily living (ADL) score by 39%, a 31% increase in their quality of life score, and a 35% increase in their sleep. No serious AEs were reported, although nearly half of the participants reported at least one AE. 60% of participants reported a reduction in their use of pain reduction medication, with 8% reporting that they no longer use any other pharmacological pain treatment.
Although the three studies featured used fairly small cohorts, and more research will have to be done to enable researchers to draw solid conclusions, they do provide the medical and scientific community with good data. These results support other studies that point towards cannabis being a safe, effective and highly tolerated treatment for patients suffering from chronic pain.