According to the Institute of Medicine, chronic pain afflicts 116 million Americans and costs the nation over $600 billion every year in medical treatment and lost productivity. Chronic pain is a devastating disease that frequently leads to significant depression and even suicide. Unfortunately, the therapeutic benefits of cannabis as an option for chronic pain are limited and extremely risky.
Spurred by efforts to encourage physicians to become more pro-active in treating chronic pain, the United States of America prescription opioids (synthetic derivatives of opium) have increased ten-fold since 1990. By 2009 prescription opioids were responsible for almost half a million emergency department visits per year. In 2010 prescription opioid overdoses were responsible for well over 16,000 deaths. A 2010 article in the New England Journal of Medicine addressing this problem is aptly titled “A Flood of Opioids, a Rising Tide of Deaths.” Drugs such as OxyContin are so dangerous that the manufacturer’s boxed warning states that “respiratory depression, including fatal cases, may occur with use of OxyContin, even when the drug has been used as recommended and not misused or abused.” Clearly safer analgesics are needed.
The Hippocratic Oath reminds to “first, do no harm.” It cannot be over-emphasised that there has never been a death from overdose attributed to cannabis. In fact, no deaths whatsoever have been attributed to the direct effects of cannabis. Cannabis has a safety record that is vastly superior to all other pain medications.
Many physicians worry that cannabis smoke might be as dangerous as cigarette smoke; however, epidemiologic studies have found no increase in oropharyngeal or pulmonary malignancies attributable to marijuana. Still, since smoke is something best avoided, medical cannabis patients are encouraged to use smokeless vaporisers which can be purchased online or at local “smoke-shops.” In states that allow cannabis dispensaries, patients can purchase “vapour pens,” analogous to e-cigarettes and fully labelled regarding doses of THC and other relevant cannabinoids.
Tests have proven that smoke-free vaporisers deliver THC as well or even more efficiently than smoking and that most patients prefer vaporisers over smoking. Like smoking, vaporisers allow patients to slowly titrate their medicine just to effect, analogous to IV patient-controlled analgesia (PCA) that has been so successful in hospital-based pain control. This avoids the unwanted psychoactive side-effects often associated with oral medication such as prescription MarinolR (100% THC in oil) capsules which tend to be slowly and erratically absorbed and are often either ineffectually weak or overpoweringly strong. Because inhaled cannabis is rapid, reliable, and titratable, most patients strongly prefer inhaled cannabis over MarinolR capsules.
While the relative safety of cannabis as the medication is quickly established, the degree of efficacy is still being established. The reported pain relief by patients in this survey is enormous. One reason for this is that patients were already self-selected for success: they had already tried cannabis and found that it worked for them. For this sample, the benefits of cannabis outweighed any adverse effects. The study design may, therefore, lend itself to over-estimating the benefits and underestimating the adverse side-effects if extrapolated to the general population.
Another reason that the reported pain relief is so significant is that cannabis has been proven effective for many forms of recalcitrant chronic pain. A University of Toronto systematic review of randomised controlled trials (RCT’s) examining cannabinoids in the treatment of chronic pain found that fifteen of eighteen trials demonstrated a significant analgesic effect of cannabinoids and that there were no serious adverse effects.
While opioids are considered to have little benefit in chronic neuropathic pain, several RCT’s have shown that cannabinoids can relieve general neuropathic pain, as well as neuropathic pain associated with HIV and with multiple sclerosis (MS). One study found that cannabis had continuing efficacy at the same dose for at least two years.
Even low dose inhaled cannabis has been proven to reduce neuropathic pain. In a randomized, double-blind, placebo-controlled crossover trial involving patients with refractory neuropathic pain, Ware, et al, found that therapeutic blood levels of THC (mean 45ng/ml achieved by a single inhalation three times a day) were much lower than those necessary to produce a cannabis euphoria or “high” (> 100ng/ml).
Cannabis is relatively non-addicting, and patients who stop using it (e.g., while travelling) report no withdrawal symptoms. One author (Webb C.) worked for twenty-six years in a high volume emergency department where he never witnessed a single visit for cannabis withdrawal symptoms, whereas dramatic symptoms from alcohol, benzodiazepine, and/or opioid withdrawal were a daily occurrence.
Medical cannabis remains controversial mainly because the federal government refuses to recognise cannabis as an accepted medication. To this we would echo the words of Melanie Thernstrom in her excellent book ‘The Pain Chronicles,’ “How could treating pain be controversial?” one might ask, “Why wouldn’t it be treated? Who are the opponents of relief?”
Cannabis is an extremely safe and effective medication for many patients with chronic pain. In stark contrast to opioids and other available pain medications, cannabis is relatively non-addicting and has the best safety record of any known pain medication (no deaths attributed to overdose or direct effects of medication). Adverse reactions are mild and can be avoided by titration of dosage using smokeless vaporisers.
More research needs to be pursued to discover degrees of efficacy in other areas of promise such as in treating anxiety, depression, bipolar disorder, autism, nausea, vomiting, muscle spasms, seizures, and many neurologic disorders. Patients deserve to have cannabis released from its current federal prohibition so that scientific research can proceed and so that physicians can prescribe cannabis with the same freedom accorded any other safe and effective medications.