“Cannabis use for medicinal purposes was first documented in 2900 BC in China, when Emperor Shen Nong described benefit for rheumatism and malaria and later in Ancient Egyptian texts.
Discussion in medical journals, the mainstream and social media around the use of cannabis for medicinal and non-medicinal purposes has increased recently, especially following the legalisation of cannabis for recreational use in Canada and the UK government’s decision to make cannabis-based medicines (CBMs) available for prescription by doctors on the specialist register.
The actual, social and economic legitimisation of cannabis and its medicinal derivatives makes it likely increasing numbers of patients will present on this class of medicines. Perioperative physicians will require a sound understanding of their pharmacology and evidence base, and may wish to exploit this group of compounds for therapeutic purposes in the perioperative period.
The increasing availability of cannabis for both recreational and medicinal purposes means that anaesthetists will encounter an increasing number of patients taking cannabis-based medications. The existing evidence base is conflicted and incomplete regarding the indications, interactions and long-term effects of these substances.
Globally, most doctors have had little education regarding the pharmacology of cannabis-based medicines, despite the endocannabinoid system being one of the most widespread in the human body.
Much is unknown, and much is to be decided, including clarifying definitions and nomenclature, and therapeutic indications and dosing. Anaesthetists, Intensivists, Pain and Perioperative physicians will want to contribute to this evidence base and attempt to harness such therapeutic benefits in terms of pain relief and opiate-avoidance, anti-emesis and seizure control.
We present a summary of the pharmacology of cannabis-based medicines including anaesthetic interactions and implications, to assist colleagues encountering these medicines in clinical practice.”
https://www.ncbi.nlm.nih.gov/pubmed/31827774
“In summary, cannabinoids may improve pain relief as part of multi-modal approach. As the evidence base increases, CBMs could become part of the perioperative teams’ armamentarium to help provide an opiate sparing multimodal analgesia regime as well as having a role in the management of common post-operative complications such as nausea and vomiting.”
“Chronic pain affects a significant percentage of the United States population, and available pain medications like opioids have drawbacks that make long-term use untenable.
“Peripheral neuropathy can significantly impact the quality of life for those who are affected, as therapies from the current treatment algorithm often fail to deliver adequate symptom relief. There has, however, been an increasing body of evidence for the use of cannabinoids in the treatment of chronic, noncancer pain. The efficacy of a topically delivered 
“Transcutaneous electrical nerve stimulation (TENS) promotes antinociception by activating the descending pain modulation pathway and consequently releasing endogenous analgesic substances.
“Medical cannabis use is an emerging topic of interest in orthopedics. Although there is a large amount of literature on medical cannabis use for managing various types of pain, few studies have focused on orthopedic conditions. There is little high-quality evidence in core orthopedic areas. The objective of this study was to summarize the literature on the efficacy of cannabis use for pain related to orthopedic conditions.
“Ecological research suggests that increased access to 
“Chronic pain is highly prevalent in most of the industrialized nations around the world. Despite the documented adverse effects, opioids are widely used for pain management. 
“The healing properties of 
“For persons living with chronic conditions, health-related quality of life (HRQoL) symptoms, such as pain, anxiety, depression, and insomnia, often interact and mutually reinforce one another.