Cannabis Effective for Reducing Neuropathic Pain, Clinical Trial Finds

A new clinical trial shows vaporized cannabis effective for reducing neuropathic pain that had otherwise shown refractory to other traditional treatments.

Cannabis effectively reduces neuropathic pain caused by spinal cord related injuries, according to a new clinical trial published in the Journal of Pain. Researchers from the University of California -San Diego, University of California – Davis, and the Sacramento VA Medical Center conducted the 8-hour human laboratory experiment.

The trial involved 42 patients that had previously found conventional pain-relieving medications, like opioids and non-steroidal anti-inflammatory drugs (NSAIDS), to be ineffective. The subjects inhaled 4 puffs of vaporized herbal cannabis containing 6.7 percent tetrahydrocannabinol (THC), 2.9 percent THC, or a placebo that contained zero THC. A second dosing, consisting of the participants’ choice of between four to eight puffs, was given three hours later. Patients then scored their level of pain using an 11-point intensity rating scale.

The researchers found that the vaporized cannabis containing 6.7 percent THC and 2.9 percent THC caused a “significant analgesic response.” While the two active doses of THC were not proven to be significantly different from each other, the researchers did note that the lower dose appeared to offer a more ideal risk-benefit ratio, as psychoactive effects were shown to be dose dependent.

“The present study complements previous investigative work that cannabis is a promising treatment in selected pain syndromes caused by injury or disease of the nervous system,” the researchers concluded.

Neuropathic pain is a chronic pain associated with damage to or a dysfunction of the body’s nervous systems. The nerve-related pain is associated with several conditions, including diabetes, multiple sclerosis, cancer, HIV, and spinal injuries or illnesses. Chronic pain is the most common cause of long-term disability. According to a 2015 study by the National Institutes of Health’s National Center for Complementary and Integrative Health (NCCIH), nearly 50 million American adults suffer from chronic or severe pain.

The study’s findings do align with earlier research, which has shown cannabis to be effective for reducing even the most refractory of pain. Studies have shown cannabis to reduce pain associated with neuropathy, cancer, headache and migraines, and spasticity. Studies also suggest that long-term use of cannabis for pain management is safe.

Of the 25 states to pass comprehensive medical marijuana programs, nearly all have approved medicinal cannabis for the treatment of chronic pain. In AlaskaArizonaCaliforniaColoradoDelawareHawaiiIllinoisMaineMarylandMichiganMontanaNew MexicoOhioOregonPennsylvaniaRhode Island and Vermont, patients with a doctor’s recommendation can access medicinal cannabis to treat their neuropathic pain.

Clinical trials on cannabis efficacy are limited due to cannabis being categorized as a Schedule I substance by the federal Drug Enforcement Administration (DEA). The Schedule I classification creates barriers to researchers. However, the DEA is currently considering reclassifying marijuana to a lower schedule. If they do so, researchers will have a much easier time examining the substance’s medicinal properties.

You can read more about the study, “An Exploratory Human Laboratory Experiment Evaluation Vaporized Cannabis in the Treatment of Neuropathic Pain from Spinal Cord Injury and Disease,” here.