BACKGROUND: Cannabis is increasingly available for the treatment of chronic pain, yet its efficacy remains uncertain.
PURPOSE: To review the benefits of plant-based cannabis preparations for treating chronic pain in adults and the harms of cannabis use in chronic pain and general adult populations.
DATA SOURCES: MEDLINE, Cochrane Database of Systematic Reviews, and several other sources from database inception to March 2017.
STUDY SELECTION: Intervention trials and observational studies, published in English, involving adults using plant-based cannabis preparations that reported pain, quality of life, or adverse effect outcomes.
DATA EXTRACTION: Two investigators independently abstracted study characteristics and assessed study quality, and the investigator group graded the overall strength of evidence using standard criteria.
DATA SYNTHESIS: From 27 chronic pain trials, there is low-strength evidence that cannabis alleviates neuropathic pain but insufficient evidence in other pain populations. According to 11 systematic reviews and 32 primary studies, harms in general population studies include increased risk for motor vehicle accidents, psychotic symptoms, and short-term cognitive impairment. Although adverse pulmonary effects were not seen in younger populations, evidence on most other long-term physical harms, in heavy or long-term cannabis users, or in older populations is insufficient.
LIMITATION: Few methodologically rigorous trials; the cannabis formulations studied may not reflect commercially available products; and limited applicability to older, chronically ill populations and patients who use cannabis heavily.
CONCLUSION: Limited evidence suggests that cannabis may alleviate neuropathic pain in some patients, but insufficient evidence exists for other types of chronic pain. Among general populations, limited evidence suggests that cannabis is associated with an increased risk for adverse mental health effects.
PRIMARY FUNDING SOURCE: U.S. Department of Veterans Affairs. (PROSPERO: CRD42016033623).
Importance: Cannabis and cannabinoid drugs are widely used to treat disease or alleviate symptoms, but their efficacy for specific indications is not clear. OBJECTIVE: To conduct a systematic review of the benefits and adverse events (AEs) of cannabinoids. Data sources: Twenty-eight databases from inception to April 2015. Study selection: Randomized clinical trials of cannabinoids for the following indications: nausea and vomiting due to chemotherapy, appetite stimulation in HIV/AIDS, chronic pain, spasticity due to multiple sclerosis or paraplegia, depression, anxiety disorder, sleep disorder, psychosis, glaucoma, or Tourette syndrome. Data extraction and systemsis: Study quality was assessed using the Cochrane risk of bias tool. All review stages were conducted independently by 2 reviewers. Where possible, data were pooled using random-effects meta-analysis. Main outcomes and measures: Patient-relevant/disease-specific outcomes, activities of daily living, quality of life, global impression of change, and AEs. RESULTS: A total of 79 trials (6462 participants) were included; 4 were judged at low risk of bias. Most trials showed improvement in symptoms associated with cannabinoids but these associations did not reach statistical significance in all trials. Compared with placebo, cannabinoids were associated with a greater average number of patients showing a complete nausea and vomiting response (47%vs 20%; odds ratio [OR], 3.82 [95%CI, 1.55-9.42]; 3 trials), reduction in pain (37%vs 31%; OR, 1.41 [95%CI, 0.99-2.00]; 8 trials), a greater average reduction in numerical rating scale pain assessment (on a 0-10-point scale; weighted mean difference [WMD], −0.46 [95%CI, −0.80 to −0.11]; 6 trials), and average reduction in the Ashworth spasticity scale (WMD, −0.36 [95%CI, −0.69 to −0.05]; 7 trials). There was an increased risk of short-term AEs with cannabinoids, including serious AEs. Common AEs included dizziness, dry mouth, nausea, fatigue, somnolence, euphoria, vomiting, disorientation, drowsiness, confusion, loss of balance, and hallucination. Conclusions and relevance: There was moderate-quality evidence to support the use of cannabinoids for the treatment of chronic pain and spasticity. There was low-quality evidence suggesting that cannabinoids were associated with improvements in nausea and vomiting due to chemotherapy, weight gain in HIV infection, sleep disorders, and Tourette syndrome. Cannabinoids were associated with an increased risk of short-term AEs. (PsycInfo Database Record (c) 2021 APA, all rights reserved)
Although many pharmacological agents are used in the therapy of neuropathic pain (NeP) due to polyneuropathy (PN), there are limited comparison studies comparing these agents. We evaluated patients with PN and related NeP in a tertiary care neuromuscular clinic with prospective follow-up after 3 and 6 months for degree of NeP using a Visual Analog Score (VAS). Clinical response to specific open-label pharmacotherapies was measured and compared for those patients not receiving pharmacotherapy. The severity of PN was quantified by the Toronto Clinical Scoring System (TCSS), with patients classified according to etiology of PN. Of a total of 408 patients referred for diagnosis and/or management of PN, NeP was identified in 182 patients (45%). NeP was most prevalent in patients with alcohol-associated PN. Pharmacotherapy management was provided in 91% of cases at first visit, and for 87% of cases after 6 months of follow-up. There were no serious adverse events for patients related to any medications, which included gabapentinoids, tricyclic antidepressants, anticonvulsants, cannabinoids and topical agents. Prevalence of intolerable side effects was similar amongst groups of medications. Approximated numbers needed to treat were similar between different individual oral pharmacotherapies, trending towards greater treatment efficacy with combination therapy. NeP is common in patients with PN and frequently requires pharmacotherapy management, which may be more effective with combination therapy. Future studies assessing longer duration of follow-up and quality of life changes with the use of various pharmacotherapies for management of NeP due to PN will be important.
INTRODUCTION: Despite the recent discovery of the potential mechanisms underlying the analgesic effects of cannabis, few clinical studies have so far assessed its analgesic effects, notably in the treatment of chronic non-malignant pain. All the studies used administration of cannabis alone. The aim of this open, pilot, study was to assess the efficacy and side effect profile of oral dronabinol (tetrahydrocannabinol - THC) in the treatment of refractory neuropathic pain.
METHODS: Seven patients (3 women/4 men), aged 60 +/- 14 years, suffering from chronic refractory neuropathic pain, received oral THC titrated to the maximum dose of 25 mg/day (mean dose: 15 +/- 6 mg), during an average of 55,4 days (range: 13-128). Various components of pain (continuous, paroxysmal and brush-induced allodynia) were assessed using VAS scores. Health-related Quality of Life (HRQL) was evaluated using the Brief Pain Inventory, and the Hospital Anxiety and Depression scale was used to measure depression and anxiety.
RESULTS: THC did not induce significant effect on the various pain, HRQL and anxiety and depression scores. Numerous side effects (notably sedation and asthenia) were observed in 5 patients out of 7, requiring premature discontinuation of the drug in 3 patients.
CONCLUSION: The present study did not reveal any significant efficacy of THC in a small cohort of patients with chronic refractory neuropathic pain, but underlined the unfavorable side effect profile of the drug. These results may partly relate to the fact that oral dronabinol exhibits a poor therapeutic ratio (efficacy at the price of side effects). The development of new and better tolerated cannabinoids is warranted.
Cannabis is increasingly available for the treatment of chronic pain, yet its efficacy remains uncertain.
PURPOSE:
To review the benefits of plant-based cannabis preparations for treating chronic pain in adults and the harms of cannabis use in chronic pain and general adult populations.
DATA SOURCES:
MEDLINE, Cochrane Database of Systematic Reviews, and several other sources from database inception to March 2017.
STUDY SELECTION:
Intervention trials and observational studies, published in English, involving adults using plant-based cannabis preparations that reported pain, quality of life, or adverse effect outcomes.
DATA EXTRACTION:
Two investigators independently abstracted study characteristics and assessed study quality, and the investigator group graded the overall strength of evidence using standard criteria.
DATA SYNTHESIS:
From 27 chronic pain trials, there is low-strength evidence that cannabis alleviates neuropathic pain but insufficient evidence in other pain populations. According to 11 systematic reviews and 32 primary studies, harms in general population studies include increased risk for motor vehicle accidents, psychotic symptoms, and short-term cognitive impairment. Although adverse pulmonary effects were not seen in younger populations, evidence on most other long-term physical harms, in heavy or long-term cannabis users, or in older populations is insufficient.
LIMITATION:
Few methodologically rigorous trials; the cannabis formulations studied may not reflect commercially available products; and limited applicability to older, chronically ill populations and patients who use cannabis heavily.
CONCLUSION:
Limited evidence suggests that cannabis may alleviate neuropathic pain in some patients, but insufficient evidence exists for other types of chronic pain. Among general populations, limited evidence suggests that cannabis is associated with an increased risk for adverse mental health effects.
