Cannabis use as a medicinal herb began many centuries ago. The earliest writings about it are from Chinese sources dating back to 2900 BC. Early civilizations utilized the herbs to treat gout, muscle spasms and joint pain as well as many other maladies. Due to legal issues, particularly in the United States, legitimate rigorous studies of the effects of Cannabis active ingredients have been difficult if not impossible. In spite of these hurdles many states have legalized medicinal use as well as some legalizing recreational use. However, the lack of true clinical data based on the normal randomized double-blind study methods utilized for other medicines make it difficult to know with certainty what is most efficacious. However, all states have included pain relief as the one recognized pharmacotherapy in their various legal statutes.
There is a plethora of anecdotal data suggesting that Cannabis is effective in treating pain, particularly chronic pain. At the moment, there are only two cannabinoids approved by the US Food and Drug Administration. Healthcare Professionals have no studies that underpin suggestions for best strains or dosing when it comes to pain relief. The authors of a study for the National Academies Committee on the Health Effects of Marijuana concluded that there is “conclusive or substantial evidence” in support of using this drug to treat chronic adult pain.
The three main pain systems include nociceptive, neuropathic and central nervous system (CNS). The nociceptive system address pain resulting from tissue damage. The other two systems involve pain that results from interpreting pain from disease states.
Tissue damage results in an immune response. This response includes secretion of histamine, serotonin, prostaglandin and others. These in turn cause elevated levels of tumor necrosis factor alpha, interluekin-1 beta, interleukin-6 and interleukin-17. The resulting pain signals travel up the peripheral nerves via the root ganglia to the thalamus. This kind of pain, often described as sharp or acute, alerts the individual to tissue damage and potentially life-threatening situations.
Neuropathic pain is caused by damage to sensory or spinal nerves. The damage causes false pain signals to transverse the nervous system and causes the patient to feel pain in places where there is tissue damage. The classic case of this is seen in diabetic melilites type 2 (adult onset diabetes). Diabetic neuropathy damages the nerve receptors such that the patient feels pain in the feet.
Evaluation and treatment of pain is not an objective issue as pain is experienced differently by different people due to their genetic makeup and life experiences. For example, the SCN9Agene alleles impact whether a person has a low or high tolerance to pain. The proximity of the observer to the patient also impacts perception of pain as the emotionally closer the observer the higher the perceived pain. This has many impacts to patient treatment including the dosing and types of drugs choices by medical professionals. Finally, pain is an affect or impacted by emotion of the patient. This means that the experienced pain is not only related to the specific SCN9A gene allele inherited by the patient, but whether they have any related psychiatric issues which might include depressive disorders, personality disorders and so on.
Treatment of pain is often accomplished by NSAIDs, COX inhibitors, opioids and other pharmacologic agents. Patients often self-medicate with alcohol as well.
Further information related to treatment and usage of Cannabis can be added to above.