Inhaling herbal cannabis vapor is effective in treating neuropathic discomfort, say the findings of a study conducted by German scientists. The observational study also found that inhaled cannabis helped neuropathic pain patients with sleep problems, a common symptom experienced by at least half of those diagnosed with the sometimes-debilitating condition.
The condition of neuropathic pain can be caused by a disease or injury that affects the nervous system. It is characterised by chronic pain and abnormal sensations called dysesthesia, or even pain when normally no pain would occur. The Cleveland Clinic reports that about 30 percent of cases of neuropathic (or chronic) pain are related to diabetes. However, other conditions such as alcoholism or shingles can cause this condition, and so can strokes, Parkinson’s Disease, multiple sclerosis and disorders affecting the nervous system. Other causes of neuropathic pain include chemotherapy, radiation therapy, phantom amputation pain, damage to nerves from surgery or trauma, and spinal cord compression. The authors of this study note that many patients do not find relief from the medications they are prescribed.
The researchers noted that the expression of neuropathy pain was highly individual. Symptoms and responses to analgesics such as antidepressants, opioids, or antiepileptics varied greatly. The researchers wrote: “Unfortunately the treatment of neuropathy pain often remains ineffective even after numerous trials using various analgesics.”
The researchers conducted the study by identifying a group of 99 participants with neuropathic chronic pain for at least three month duration who also had severe symptoms, and were unable to receive other forms of treatment. In Germany, medical cannabis use was made legal in 2017. This was for chronic diseases that had already exhausted conventional treatments. Participants received dried herbs of herbal cannabis which can be obtained in German pharmacies with a prescription. The THC content of cannabis used by all patients was between 12-22%. Nearly two thirds of the participants (64%) used cannabis that had a THC strength of 16-22%. Inhaling cannabinoids was instructed by the patients using a vaporizer. Over a six-month period, participants were able to choose their own method of administering cannabis, whether they used it according to a schedule, when time allowed, or in response to a painful attack.
The study required participants to complete a video consult with a doctor every four-six weeks during the six month study period. A scale of 0-10 was used to assess pain. According to the German Pain Society (DPG), pain scores over 6 indicate severe pain that significantly impacts a patient’s life quality. The severity of sleep disruption was assessed on a scale ranging from 0-10. According to National Institutes of Health, 50% to 80% of patients with neuropathic chronic pain experience sleeping problems. The severity of these sleep disturbances is often related to pain intensity.
In six weeks, the median pain score dropped from 7.5 down to 4.0. The proportion of patients with severe pain (score >6) decreased from 96 percent to 16 percent,” the researchers wrote. The median score for sleep disturbance decreased significantly from 8.0 down to 2.0. The improvement was sustained up to a six-month period. “There were no serious adverse reactions reported.”
Researchers Report Improvements to Pain and Sleep in Study Participants
The majority of patients were suffering from severe neuropathy at the beginning of the research. 96% had a pain rating above 6, and the median score for the entire group was 7.5. In the six-week period following treatment initiation, 90% reported improvement of their overall condition. Pain was also significantly decreased to a median score of 3.75. In five further follow-up sessions, the pain score continued to decrease before stabilizing about 3.
Prior to using medical cannabis, the majority of patients had severe sleep disorders with an average score of 8. The first post-consultation report showed a marked improvement in sleep. Sleep disturbance scores dropped from 3 to 2 and remained at this level until the end six months of observation. Researchers said that improvements in sleep were likely due to an improvement in symptoms of pain but that there was also a possibility that a direct result from medical marijuana played a part. The majority of patients experienced adequate sleep quality, “a critical parameter for life quality.”
One or more interviews after the observation period revealed that 97 patients (99%) reported an improvement to their overall condition. Participants in the study reported mild side-effects, including fatigue (4.8%), dry mucous tissues (5.4%) and an increased appetite (2.7%). Researchers concluded in their report that these results showed that medical cannabis can effectively and safely treat chronic neuropathic symptoms.
Researchers admitted that there were some limitations to the study. One of these was a bias towards patients who would be more receptive to medical marijuana inhalation. They also noted missing data and incomplete data, which were deemed “a weakness inherent to a retrospective study.”
The peer-reviewed Journal published a report last month on research entitled “Medical Cannabis Alleviates chronic Neuropathic pain Effectively and Sustainable without Severe Side Effects: A Retrospective study on 99 cases.” Medical Cannabis Cannabinoids.