CHRONIC PAIN

BY MICHELLE MARTIN

Pain is like a warning signal to take care of an injury or illness. Chronic pain, however, is pain that continues when there is no good reason for it anymore. It’s as though the signal won’t shut off for months or years after the person is aware of a problem or even after it has healed. At best, this pain is a nuisance and at worst, it is debilitating.

Acute pain is pain that is the direct result of illness or injury and has a distinct beginning and end. In contrast, persistent or chronic pain is defined as pain that continues three to six months beyond the usual recovery period, or that goes on for months or years due to a chronic condition. “The pain is usually not constant but can interfere with daily life at all levels,” according to the American Chronic Pain Association. The association reported in 2002 that more than 50 million Americans suffer from chronic pain each year. 1

A person with chronic pain is likened to a car with four flat tires in a video put out by the American Chronic Pain Association. Medical treatment may work to fill one tire, but the other tires are still flat, and the car cannot go. The video’s message: it often takes a combination of various interventions to fill all the tires or adequately address someone’s chronic pain and allow them to continue their life’s journey. The Association advocates a “multimodal strategy,” in which a patient incorporates an individualized blend of techniques. These might include self-care activities, such as exercise or meditation; both mind and body-focused therapies provided by professionals; and modalities and medicines prescribed by health-care providers.

The Association’s 2019 edition 2 of pain management techniques lists about three dozen therapies. It also introduces a number of pain medications, including acetaminophen, NSAIDs (non-steroidal anti-inflammatory drugs), opioids, antidepressants, antiepileptics, and muscle relaxants. Patients often take medications in which the benefits outweigh the risks or side-effects. Common side-effects of pharmaceutical treatments include insomnia, skin rash, headache, swelling, stomach pain, diarrhea or constipation, confusion, breathing difficulties, abnormal heartbeat, and increased blood pressure.

Cannabis is still a somewhat controversial treatment that might help to fill that first tire in the car analogy. 64% of board-certified pain specialists in Israel recently responded to a survey about cannabis. 3 Nearly all of the respondents prescribe cannabis, and 63% find it moderately to highly effective, while 56% encountered mild or no side effects, and 5% perceive it as significantly harmful. A 2019 study 4 by the Veterans Health Administration found that many people substitute cannabis for opioids. Of the 486 people who had reported using both marijuana and opioids in the previous year, 41 percent reported decreasing or stopping opioid use altogether due to marijuana use.

It is important to note that most current evidence suggests a difference in pain relief based on the type of pain, the type of cannabis products, and the way they are delivered.

Two major categories of physical pain are neuropathic pain (pain that affects the nerves or nervous system) and nociceptive pain (pain that results from a painful stimulus or injury). It turns out that cannabis is more likely to help with neuropathic pain. In 2014, 5 The American Academy of Neurology concluded oral cannabis extracts may work for some kinds of spasticity and pain in patients with MS, though more research on safety would be helpful. Three years later, in 2017, National Academies of Sciences, Engineering and Medicine agreed that patients treated with cannabis or related products were likely to have a significant reduction in pain symptoms. 6 That same year, a review of 27 studies that was part of a larger Veterans Health Administration study found there is limited evidence cannabis can help alleviate neuropathic pain. 7 The authors site low confidence, because there were inconsistent results of short studies using different formulations and delivery mechanisms that seemed to have little applicability to what was actually available in dispensaries at the time.

In a 2019 study that was open-label (so no control group), but had more than 30,000 participants, researchers looked at whether patients with severe chronic pain would benefit from an equal parts THC-CBD mouth spray in addition to their regular pain management routines. 8 The spray appeared to significantly reduce pain for those suffering from neuropathic pain, had some effect for those with a mix of pain types, but had no effect for those with only nociceptive chronic pain.

One 2017 systematic review of randomized controlled trials found that inhalation provided the most promise for consistent pain relief. Nanotechnology is another technique researchers are exploring as a possible delivery method in the realm of pain. 9

In a 2018 review of the research, authors agreed that there is moderate evidence that cannabis can relieve chronic neuropathic pain. 10 They go on to cite research findings that explain how cannabinoids’ analgesic effects might come about. Among other things, cannabinoids can inhibit presynaptic nerve endings from releasing neurotransmitters, including neuropeptides; modulate the postsynaptic excitability; activate the brain’s top-down inhibition of pain; and reduce nerve inflammation.