Cannabinoids are safe and effective for the treatment of chronic pain, according to the results of a systematic review of randomized controlled trials published in the Journal of Neuroimmune Pharmacology.
Investigators from Dalhousie University in Halifax, Nova Scotia and McGill University in Montreal evaluated the results of 11 placebo-controlled trials conducted between the years 2010 and 2014. Trials assessed the use of various types of cannabinoid preparations, including herbal cannabis, liquid and oral cannabis extracts, and nabilone (a synthetic analog of THC), in pain treatment.
Cannabinoids possessed “significant analgesic effects” and were “well tolerated” in the majority of studies reviewed.
Authors concluded, “The current systematic review provides further support that cannabinoids are safe, demonstrate a modest analgesic effect and provide a reasonable treatment option for treatment chronic non-cancer pain.”
A 2011 review of 18 separate randomized trials evaluating the safety and efficacy of cannabinoids for pain management similarly reported, “[C]annabinoids are a modestly effective and safe treatment option for chronic non-cancer (predominantly neuropathic) pain.”
In September, Canadian researchers reported that pain patients who consumed herbal cannabis daily for one-year experienced decreased analgesia and no increase in serious adverse side effects compared to matched controls.
An abstract of the study, “Cannabinoids for the treatment of chronic non-cancer pain: An updated systematic review of randomized controlled trials,” appears online here.
Vaporized cannabis mitigates pain intensity in diabetic subjects in a dose-dependent manner, according to clinical trial data published online ahead of print in The Journal of Pain.
Investigators at the University of California, San Diego assessed the efficacy of inhaled cannabis versus placebo in 16 patients with painful diabetic peripheral neuropathy (DPN).
Authors reported: “This small, short-term, placebo-controlled trial of inhaled cannabis demonstrated a dose-dependent reduction in diabetic peripheral neuropathy pain in patients with treatment-refractory pain. … Overall, our finding of an analgesic effect of cannabis is consistent with other trials of cannabis in diverse neuropathic pain syndromes.”
A series of clinical trials conducted by investigators affiliated with the Center for Medicinal Cannabis Research at the University of California, San Diego previously reported that the inhalation of whole-plant cannabis is efficacious in the treatment of various types of treatment-resistant neuropathic pain, including HIV-associated neuropathy and spinal cord injury. According to the findings of a 2014 clinical trial published in the Journal of Pain and Palliative Care Pharmacotherapy, “At least 10 randomized controlled trials, lasting for more than 1000 patients, have demonstrated efficacy of different types of cannabinoids for diverse forms of neuropathic pain.”
An abstract of the study, “Efficacy of inhaled cannabis on painful diabetic neuropathy,” appears online here.
The administration of a single dose of whole-plant cannabis via a thermal-metered inhaler is effective and well tolerated among patients suffering from neuropathy (nerve pain), according to clinical trial data published online ahead of print in the Journal of Pain and Palliative Care Pharmacotherapy.
Israeli investigators assessed the efficacy of a novel, portable metered-dose cannabis inhaler in eight subjects diagnosed with chronic neuropathic pain. Researchers reported that the device administered an efficient, consistent, and therapeutically effective dosage of cannabinoids to all participants.
They concluded, “This trial suggests the potential use of the Syqe Inhaler device as a smokeless delivery system of medicinal cannabis, producing a delta-9-THC pharmacokinetic profile with low inter-individual variation of (maximum drug/plasma concentrations), achieving pharmaceutical standards for inhaled drugs.”
A series of clinical trials conducted by investigators affiliated with the Center for Medicinal Cannabis Research at the University of California, San Diego previously determined that the inhalation of whole-plant cannabis is efficacious in the treatment of neuropathic pain.
Full text of the study, “The pharmacokinetics, efficacy, safety, and ease of use of a novel portable metered-dose cannabis inhaler in patients with chronic neuropathic pain: A phase 1a study,” will appear in the Journal of Pain and Palliative Care Pharmacotherapy.
The administration of synthetic cannabinoid agonists limits HIV infection in macrophages (white blood cells that aid in the body’s immune response), according to preclinical data published in the Journal of Leukocyte Biology. Macrophages are one of the first type of cells infected by the HIV virus when it enters the body.
Investigators at Temple University School of Medicine in Philadelphia assessed the impact of three commercially available synthetic THC agonists on HIV-infected macrophage cells. Following administration, researchers sampled the cells periodically to measure the activity of an enzyme called reverse transcriptase (RT), which is essential for HIV replication. By day 7, investigators reported that the administration of all three compounds was associated with a significant decreased in HIV replication.
Stated a Temple University Health System press release: “The results suggest that selective CB2 (cannabinoid 2 receptor) agonists could potentially be used in tandem with existing antiretroviral drugs, opening the door to the generation of new drug therapies for HIV/AIDS. The data also support the idea that the human immune system could be leveraged to fight HIV infection.”
Patients living with HIV/AIDS frequently report consuming cannabis to counter symptoms of anxiety, appetite loss, chronic pain, and nausea, and one study has reported that patients who use cannabis therapeutically are 3.3 times more likely to adhere to their antiretroviral therapy regimens than non-cannabis users. In preclinical models, the long-term administration of delta-9-THC has recently been associated with decreased mortality and ameliorated disease progression in monkeys. In clinical models, cannabis inhalation is associated with decreased neuropathy and increased levels of appetite hormones in the blood of subjects with HIV infection.
The abstract of the study, “Attenuation of HIV-1 replication in macrophages by cannabinoid receptor 2 agonists,” appears online here.
Investigators at the University of California, Davis Medical Center conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in 39 subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Subjects inhaled cannabis of either moderate THC (3.53 percent), low dose THC (1.29 percent), or zero THC (placebo). Subjects continued to take all other concurrent medications as per their normal routine during the 3- to 4-week study period. Spontaneous pain relief, the primary outcome variable, was assessed by asking participants to indicate the intensity of their current pain on a 100-mm visual analog scale (VAS) between 0 (no pain) and 100 (worst possible pain).
Researchers reported: “Both the low and medium doses proved to be salutary analgesics for the heterogeneous collection of neuropathic pain conditions studied. Both active study medications provided statistically significant 30% reductions in pain intensity when compared to placebo.”
They concluded: “Both the 1.29% and 3.53% vaporized THC study medications produced equal antinociception at every time point. … [T]he use of low doses could potentially be prescribed by physicians interested in helping patients use cannabis effectively while minimizing cognitive and psychological side effects. Viewed with this in mind, the present study adds to a growing body of literature supporting the use of cannabis for the treatment of neuropathic pain. It provides additional evidence of the efficacy of vaporized cannabis as well as establishes low-dose cannabis (1.29%) as having a favorable risk-benefit ratio.”
Previous clinical trials have indicated that inhaled cannabis can safety and effectively relieve various types of pain, particularly neuropathy — a hard-to-treat nerve condition often associated with cancer, HIV, spinal cord injury, diabetes, multiple sclerosis, and other conditions. These include the following double-blind, placebo-controlled (FDA gold-standard) studies:
Ware et al. 2010. Smoked cannabis for chronic neuropathic pain: a randomized controlled trial. CMAJ 182: 694-701.
Wilsey et al. 2008. A randomized, placebo-controlled, crossover trial of cannabis cigarettes in neuropathic pain. Journal of Pain 9: 506-521.
Ellis et al. 2008. Smoked medicinal cannabis for neuropathic pain in HIV: a randomized, crossover clinical trial. Neuropsychopharmacology 34: 672-80.
Abrams et al. 2007. Cannabis in painful HIV-associated sensory neuropathy: a randomized placebo-controlled trial. Neurology 68: 515-521.
Wallace et al. 2007. Dose-dependent Effects of Smoked Cannabis on Capsaicin-induced Pain and Hyperalgesia in Healthy Volunteers Anesthesiology 107: 785-796.
Separate clinical trial data also reports that inhaled “cannabis augments the analgesic effect of opioids” and therefore “may allow for opioid treatment at lower doses with fewer side effects.”
Since 1999, US sales of opiate drugs have tripled in number and in 2010, a record-setting 254 million prescriptions for opioids were filled in the United States — enough to medicate every American adult around the clock for a month. (In particular, the manufacturing of the drug Oxycodone has increased from 8.3 tons in 1997 to 105 tons in 2011, an increase of 1,200 percent.) Overdose deaths from the use of prescription painkillers are also now at record levels, totaling some 15,000 annually — more than triple the total a decade ago.
Full text of the study, “Low-dose vaporized cannabis significantly improves neuropathic pain,” appears in The Journal of Pain.