Cannabinoids in the management of chronic pain: a front line clinical perspective.

Posted on November 19, 2015 by David

“Chronic pain is an escalating public health problem. Currently available treatments are inadequate to control chronic pain conditions, and there is a critical need for novel treatments.

Over a half century of elegant preclinical research has identified the presence of a sophisticated endocannabinoid system that is part of our natural pain and immune defense network.

Convergent work has supported the significant potential to exploit this system to decrease pain and inflammation.

Although the clinical research remains in its infancy, recent systematic reviews have found that 25 of 30 randomized controlled trials have demonstrated a significant analgesic effect.

The authors concluded that cannabinoids currently available for clinical use demonstrate a modest analgesic effect and are safe for the management of chronic pain.

There is a critical need for more translational research so that the excellent work of Dr. Itai Bab and our basic science colleagues around the world can move forward in providing novel cannabinoid-based medicines.

This should include more potent analgesics that are limited in side effects with several routes of delivery. Our patients deserve additional agents for pain control with a novel mechanism of action, and cannabinoids are the new frontier.”

http://www.ncbi.nlm.nih.gov/pubmed/26581068

The prescription of medical cannabis by a transitional pain service to wean a patient with complex pain from opioid use following liver transplantation: a case report.

Posted on October 29, 2015 by David

Canadian Journal of Anesthesia/Journal canadien d'anesthésie

“The purpose of this case report is to describe a patient with a preoperative complex pain syndrome who underwent liver transplantation and was able to reduce his opioid consumption significantly following the initiation of treatment with medical cannabis.

CLINICAL FEATURES:

A 57-yr-old male with a history of hepatitis C cirrhosis underwent liver transplantation. Preoperatively, he was taking hydromorphone 2-8 mg⋅day-1 for chronic abdominal pain. Postoperatively, he was given intravenous patient-controlled analgesia through which he received hydromorphone 30 mg⋅day-1. Our multidisciplinary Transitional Pain Service was involved with managing his moderate to severe acute postsurgical pain in hospital and continued with weaning him from opioid medications after discharge. It was difficult to wean the patient from opioids, and he was subsequently given medical cannabis at six weeks postoperatively with remarkable effect. By the fifth postoperative month, his use of opioids had tapered to 6 mg⋅day-1 of hydromorphone, and his functional status was excellent on this regimen.

CONCLUSION:

Reductions in opioid consumption were achieved with the administration of medical cannabis in a patient with acute postoperative pain superimposed on a chronic pain syndrome and receiving high doses of opioids. Concurrent benefits of initiating medical cannabis may include improvements in pain profile and functional status along with reductions in opioid-related side effects. This highlights the potential for medical cannabis as an adjunct medication for weaning patients from opioid use.”

http://www.ncbi.nlm.nih.gov/pubmed/26507533

https://link.springer.com/article/10.1007%2Fs12630-015-0525-6

Peripherally Restricted Cannabinoids for the Treatment of Pain.

Posted on October 27, 2015 by David

“The use of cannabinoids for the treatment of chronic diseases has increased in the United States, with 23 states having legalized the use of marijuana.

Although currently available cannabinoid compounds have shown effectiveness in relieving symptoms associated with numerous diseases, the use of cannabis or cannabinoids is still controversial mostly due to their psychotropic effects (e.g., euphoria, laughter) or central nervous system (CNS)-related undesired effects (e.g., tolerance, dependence).

A potential strategy to use cannabinoids for medical conditions without inducing psychotropic or CNS-related undesired effects is to avoid their actions in the CNS.

This approach could be beneficial for conditions with prominent peripheral pathophysiologic mechanisms (e.g., painful diabetic neuropathy, chemotherapy-induced neuropathy).

In this article, we discuss the scientific evidence to target the peripheral cannabinoid system as an alternative to cannabis use for medical purposes, and we review the available literature to determine the pros and cons of potential strategies that can be used to this end.”

http://www.ncbi.nlm.nih.gov/pubmed/26497478

Medical Cannabis Effective for Chronic Pain, Other Indications

Posted on September 28, 2015 by David

“According to this study:

* Moderate-quality evidence supports the use of cannabinoids for the treatment of chronic pain and for the spasticity related to multiple sclerosis.

* Low-quality evidence suggests that cannabinoids may be effective for chemotherapy-induced nausea and vomiting and other indications.”

http://journals.lww.com/ajnonline/Abstract/2015/10000/Medical_Cannabis_Effective_for_Chronic_Pain,_Other.31.aspx

https://www.researchgate.net/publication/282153137_Medical_Cannabis_Effective_for_Chronic_Pain_Other_Indications

“Medical Cannabis Effective for Chronic Pain, Other Indications. According to this study.” http://www.ncbi.nlm.nih.gov/pubmed/26402288

“Cannabinoids for Medical Use: A Systematic Review and Meta-analysis” http://jama.jamanetwork.com/article.aspx?articleid=2338251

Cannabis for the Management of Pain: Assessment of Safety Study (COMPASS).

Posted on September 20, 2015 by David

“Cannabis is widely used as a self-management strategy by patients with a wide range of symptoms and diseases including chronic noncancer pain.

The safety of cannabis use for medical purposes has not been systematically evaluated. We conducted a prospective cohort study to describe safety issues among subjects with chronic noncancer pain.

A standardized herbal cannabis product (12.5% THC) was dispensed to eligible subjects for a one-year period; controls were subjects with chronic pain from the same clinics who were not cannabis users.

The primary outcome consisted of serious adverse events (SAEs) and non-serious adverse events (AEs). Secondary safety outcomes included pulmonary and neurocognitive function and standard hematology, biochemistry, renal, liver and endocrine function.

Secondary efficacy parameters included pain and other symptoms, mood, and quality of life.

Two hundred and sixteen individuals with chronic pain were recruited to the cannabis group (141 current users and 58 ex-users) and 215 controls (chronic pain but no current cannabis use) from seven clinics across Canada. The median daily cannabis dose was 2.5g/d.

There was no difference in risk of SAEs between groups.

Medical cannabis users were at increased risk of non-serious AEs; most were mild to moderate. There were no differences in secondary safety assessments.

Quality-controlled herbal cannabis, when used by cannabis-experienced patients as part of a monitored treatment program over one year, appears to have a reasonable safety profile.

This study evaluated the safety of cannabis use by patients with chronic pain over one year. The study found that there was a higher rate of adverse events among cannabis users compared to controls but not for serious adverse events at an average dose of 2.5g herbal cannabis per day.”

http://www.ncbi.nlm.nih.gov/pubmed/26385201

http://www.thctotalhealthcare.com/category/pain-2/

The effects of endocannabinoid receptor agonist anandamide and antagonist rimonabant on opioid analgesia and tolerance in rats.

Posted on September 17, 2015 by David

“The role of the cannabinoid (CB) system in the tolerance to analgesic effect of opioid remains obscure. The aim of the present study was to evaluate the effects of the endocannabinoid nonselective receptor agonist anandamide (AEA) and CB1 receptor antagonist rimonabant (SR141716) on morphine analgesia and tolerance in rats.

The findings suggested that AEA in combination with morphine produced a significant increase in expression of analgesic tolerance to morphine.

Conversely, cannabinoid receptor antagonist SR141716 attenuated morphine analgesic tolerance.

In addition, administration of AEA with morphine increased morphine analgesia.

In conclusion, we observed that the cannabinoid receptor agonist anandamide and CB1 receptor antagonist SR141716 plays a significant role in the opioid analgesia and tolerance.”

http://www.ncbi.nlm.nih.gov/pubmed/26374993

High Times for Painful Blues: The Endocannabinoid System in Pain-Depression Comorbidity.

Posted on September 7, 2015 by David

“Depression and pain are two of the most debilitating disorders worldwide and have an estimated cooccurrence of up to 80%. Comorbidity of these disorders is more difficult to treat, associated with significant disability and impaired health-related quality of life than either condition alone, resulting in enormous social and economic cost.

Several neural substrates have been identified as potential mediators in the association between depression and pain, including neuroanatomical reorganization, monoamine and neurotrophin depletion, dysregulation of the hypothalamo-pituitary-adrenal axis, and neuroinflammation.

However, the past decade has seen mounting evidence supporting a role for the endogenous cannabinoid (endocannabinoid) system in affective and nociceptive processing, and thus, alterations in this system may play a key role in reciprocal interactions between depression and pain.

This review will provide an overview of the preclinical evidence supporting an interaction between depression and pain and the evidence supporting a role for the endocannabinoid system in this interaction.”

http://www.ncbi.nlm.nih.gov/pubmed/26342110

“The plant Cannabis sativa has been used as a medicine throughout the world for several thousand years, with reports of its use in treating painful symptoms appearing as early as 2600 BC. The principal psychoactive ingredient of Cannabis sativa, delta-9-tetrahydrocannabinol (Δ9-THC), was first identified in 1964, and subsequent studies to understand its mechanism of action led to the discovery of the endogenous cannabinoid (endocannabinoid) system… Because of the distribution of the endocannabinoid system throughout spinal and supraspinal regions, it is in a prime position to regulate neurophysiological activities such as affective and nociceptive processing… evidence suggests a prominent role for the endocannabinoid system in the interaction between depression and pain,” http://ijnp.oxfordjournals.org/content/early/2015/09/04/ijnp.pyv095.long

Medical Marijuana and Chronic Pain: a Review of Basic Science and Clinical Evidence.

Posted on September 3, 2015 by David

“Cannabinoid compounds include phytocannabinoids, endocannabinoids, and synthetics.

The two primary phytocannabinoids are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), with CB1 receptors in the brain and peripheral tissue and CB2 receptors in the immune and hematopoietic systems.

The route of delivery of cannabis is important as the bioavailability and metabolism are very different for smoking versus oral/sublingual routes.

Gold standard clinical trials are limited; however, some studies have thus far shown evidence to support the use of cannabinoids for some cancer, neuropathic, spasticity, acute pain, and chronic pain conditions.”

http://www.ncbi.nlm.nih.gov/pubmed/26325482

Neuropeptide VF Enhances Cannabinoid Agonist WIN55,212-2-Induced Antinociception in Mice.

Posted on August 15, 2015 by David

“Cannabinoids produce analgesia in several pain models, but the undesirable side effects from high doses of cannabinoid drugs limit their clinic use.

Our recent results indicate that cannabinoid-induced antinociception was enhanced by neuropeptide VF (NPVF).

Here, we investigate whether low-dose cannabinoid agonists combined with NPVF can produce effective antinociception with limited side effects…

These data suggest that the cannabinoid agonist combined with NPVF produces effective antinociception-lacking tolerance via both cannabinoid receptor type 1 and neuropeptide FF receptors in the brain.”

http://www.ncbi.nlm.nih.gov/pubmed/26273748

[Clinical pharmacology of medical cannabinoids in chronic pain].

Posted on August 14, 2015 by David

“In Switzerland, medical cannabinoids can be prescribed under compassionate use after special authorization in justified indications such as refractory pain. Evidence of efficacy in pain is limited and the clinical benefit seems to be modest. Their drug-drug interactions (DDI) profile is poorly documented. Cytochromes P450 (CYP) 2C9 and 3A4 are involved in the metabolism of tetrahydrocannabinol and cannabidiol, which implies possible DDI with CYP450 inhibitor and inducer, such as anticonvulsivants and HIV protease inhibitors, which may be prescribed in patients with neuropathic pain.”

http://www.ncbi.nlm.nih.gov/pubmed/26267945