Chronic Pain

Severe chronic pain seems to be the major reasons why patients use cannabis medicinally.
There are many types of pain and not all of them respond the same to cannabis. The therapeutic effects of cannabinoids seem to be most pronounced in neuropathic types of pain, meaning that the pain originates from damage or disease that affects the sensory nerves. 

This is the case for example in multiple sclerosis (MS), where the patients’ nerves are being attacked by his own immune system; or bromyalgia, where the nerves become hypersensitive and record even a mild touch as pain. In contrast, studies measuring the effects on acute pain (e.g. postoperative pain) often show no effects. 

Most likely, this difference can be explained by the different role the endocannabinoids play in both types of pain. Studies on severe pain indicate that the majority of cannabinoid side effects are preferable over the side effects caused by the prolonged use of high doses of conventional opioid medication.

Chronic neuropathic pain is a common and difficult to treat condition that has limited treatment options. As a consequence, even modest therapeutic effects of cannabinoids may be relevant to suffering patients. It is interesting to note that a selective beneficial effect on women was observed in some chronic pain studies. 

This may be an indication that certain cannabinoids can help alleviate chronic pain conditions which predominantly affect women, such as fibromyalgia. Because chronic pain is so difficult to treat with any single medicine, cannabinoids have often been studied in combination with other pain medication, including strong opioids such as morphine. It was found that cannabinoids and opioids can work together, in such a way that their combined effect is stronger than may be expected. 

This effect is called ‘synergy’. As a result, addition of cannabinoids can often result in a lowering of the dose of opioids needed, thereby reducing the potentially severe side effects (e.g. respiratory depression) of opioid medicines.