“Cannabinoids block pain responses in virtually every laboratory pain model tested.
In models of acute or physiological pain, cannabinoids are highly effective against thermal, mechanical, and chemical pain, and are comparable to opioids in potency and efficacy.1 In models of chronic pain, cannabinoids exhibit efficacy in the modulation of both inflammatory2 and neuropathic pain.3
Recent reviews describe an endogenous cannabinoid system involved in pain modulation that produces analgesia through the same brainstem circuitry involved in opioid analgesia.1., 4., 5., 6. Although co-administration of Δ-9-tetrahydrocannabinol (THC) with μ opioid agonists can potentiate the antinociceptive effects of each agent, an opioid is not required for cannabinoid analgesia.5., 6. Co-administration of a cannabinoid may lead to a lower opioid requirement. In an N-of-1 trial, oral THC reduced the pain of familial Mediterranean fever such that the use of breakthrough opioid for pain relief decreased significantly.7
Recently, in Canada, the Medical Marijuana Access Program allows patients to apply to Health Canada for access to dried cannabis for medicinal purposes. Although smoked cannabis is not an ideal delivery system, it is efficient and results in plasma concentration curves parallel to those seen after intravenous administration.8 We present three patients who used small doses of smoked marijuana in combination with an opioid.
These cases are consistent with preclinical work demonstrating that cannabinoids exhibit analgesic effects and may potentiate the antinociceptive effects of opioids. These patients were able to decrease the dose of opioid by 60–100% as compared to before the regular use of smoked marijuana. With the introduction of smoked marijuana, each patient reported better pain control.
Unfortunately, the source of smoked marijuana used by patients, and the percentage of THC in it, is unknown. All patients reported previous exposure to cannabis at some time in their lives before the onset of their pain, and the relevance of this experience also is unknown. Standardized measures of pain were not used, and the information presented was based on the patients’ verbal report when they presented for follow-up appointments at the Pain Management Unit. Nonetheless, these cases suggest that further research regarding the role of cannabinoids as analgesics and the combination of cannabinoids with opioids in the control of pain is needed.”
http://www.jpsmjournal.com/article/S0885-3924(03)00142-8/fulltext]]>
“Cannabis sativa has long been used for medicinal purposes.
To improve safety and efficacy, compounds from C. sativa were purified or synthesized and named under an umbrella group as 
“Medical marijuana is increasingly prescribed as an analgesic for a growing number of indications, amongst which terminal cancer and multiple sclerosis.
In this study we aimed to investigate the immune-cell modulatory properties of medical cannabis.
Healthy volunteers were asked to ingest medical cannabis, and kinome profiling was used to generate comprehensive descriptions of the cannabis challenge on inflammatory signal transduction in the peripheral blood of these volunteers.
Results were related to both short term and long term effects in patients experimentally treated with a medical marijuana preparation for suffering from abdominal pain as a result of chronic pancreatitis or other causes.
The results reveal an immunosuppressive effect of cannabinoid preparations via deactivation of signaling through the pro-inflammatory p38 MAP kinase and mTOR pathways and a concomitant deactivation of the pro-mitogenic ERK pathway. However, long term cannabis exposure in two patients resulted in reversal of this effect.
While these data provide a powerful mechanistic rationale for the clinical use of medical marijuana in inflammatory and oncological disease, caution may be advised with sustained use of such preparations.”
“Early attention to pain and symptoms in those with cancer improves both quality of life and survival. Opioid medications are the mainstay treatment of cancer-related pain.