Investigation of Cannabis for Chronic Pain and Palliative Care

Investigation of Cannabis for Chronic Pain and Palliative Care

The use of cannabis for severe medical conditions is being legalized in different states, increasing the mandate to make cannabis legal for medically ill patients. However, there is a lack of placebo-controlled studies investigating the efficacy of cannabis. Dronabinol (synthetic, oral Δ-9-THC) is FDA approved for the appetite stimulation in AIDS-related anorexia and nausea/vomiting in chemotherapy patients. Nabilone, a synthetic analogue of THC, is approved for nausea/vomiting in chemotherapy patients. These medications have been found to be effective for these disorders, but there remains an interest in studying cannabis, partly due to the numerous cannabinoids contained within the cannabis plant. Among these is cannabidiol, which does not produce subjective effects, but has been shown to have potent anti-inflammatory effects. In addition, there is data indicating that cannabidiol may be effective for neuropathic pain and nausea/vomiting.

The goal is to investigate the effects of high CBD/low THC cannabis on symptoms such as pain, nausea/vomiting, and quality of life in seriously ill participants. While there is data beginning to emerge that cannabis may have a beneficial effect on these symptoms, there are few placebo controlled, double-blind studies. Additionally, the administration of cannabis to medically ill patients may be limited by its subjective effects, such as anxiety, intoxication, or paranoia. Most cannabis available today has high levels of Δ-9-THC (about 15%). By using cannabis that is high in CBD, but low in - Δ-9-THC, it is hypothesized that some of these effects can be avoid, while maximizing the therapeutic effects, if any.

The goal of this study is to perform a double-blind, placebo-controlled study to investigate the efficacy of cannabis, compared to placebo, in medically ill participants seeking relief symptoms such as pain, nausea, and vomiting. Participants who meet criteria for severe conditions will be referred from their clinicians . Cannabis that has a high concentration of cannabidiol, which is a cannabinoid that does not change perception or produce intoxication, and low in Δ-9-THC will be used. In this way, the hope is to maximize the benefit of cannabis, while lowering the possible side effects of cannabis in medically ill participants.

The overall goal of this study is to compare active high cannabidiol (CBD)/ low (-)-trans-Δ9- tetrahydrocannabinol (THC) cannabis vs placebo cannabis in patients with serious medical disorders. Participants will be referred from clinicians and will come to the laboratory daily (3-5 times weekly) for cannabis (15.76% CBD; 3.11% Δ-9-THC) vs placebo (0.0% CBD/ 0.01% Δ-9-THC). The cannabis will be vaporized or smoked as a cannabis cigarette. The participants can choose which option they prefer. The cross-over design will be used where participants receive 2 weeks of active cannabis vs two weeks of placebo in counterbalanced order, with participants blinded to the condition. The outcome measures primarily include measures of pain, with secondary measures of mood, nausea/appetite, quality of life, and the both the potentially positive and negative subjective effects of cannabis (e.g., high, mellow, anxious, paranoid).

Inclusion Criteria:

1. One of the medical diagnoses (cancer, amyotrophic lateral sclerosis, Parkinson's disease, spinal cord injury, neuropathy, and phantom limb pain, thalamic pain, pain related to injury of nerve plexus/plexi, and neuropathic facial pain), with reports of pain (at least 3 on item 3 on the 9 item Brief Pain Inventory)that remains despite their current medical treatment.
2. Age 21-60
3. Able to give informed consent, and comply with study procedures
4. Experience inhaling substances.

Exclusion Criteria:

1. Meet DSM-V criteria for current major psychiatric illness, such as bipolar disorder, major depression, active suicidality, or psychosis, that could be exacerbated by the administration of cannabis
2. Meet criteria for major neurological disorder, such as mild cognitive impairment or neurodegenerative disorders (such as movement disorders, dementia), that could be exacerbated by the administration of cannabis.
3. Women who are not practicing an effective form of birth control (condoms, diaphragm, birth control pill, IUD) or currently pregnant
4. Current (weekly) use of cannabis
5. Participants on supplemental oxygen
6. Participants with a substance use disorder involving marijuana or opioids.