By Pat Anson, PNN Editor

Cannabis may be an effective way to reduce acute and chronic pain in patients with sickle cell disease, according to a small pilot study published in JAMA Network Open.

Sickle cell is a genetic disease that affects about 100,000 people in the U.S., mostly of African or Hispanic descent. Their red blood cells are rigid and sickle-shaped, which causes blockages in blood vessels, starves tissues and organs of oxygen, and causes periods of intense pain.

Researchers at UC Irvine and UC San Francisco enrolled 23 adult sickle cells patients in a placebo-controlled study to see if inhaled cannabis could be a safe adjunct to opioid medication in treating sickle cell pain. Most patients continued to use opioids during the course of the five-day trial. Participants inhaled either vaporized cannabis or a placebo three times a day. The cannabis had an equal ratio of CBD and THC – the psychoactive ingredient in cannabis.

As the five-day study period progressed, patients who inhaled cannabis reported that pain interfered less and less with their daily activities, such as walking and sleeping, and there was a significant drop in how much pain affected their mood. The decline in pain levels was not considered statistically significant, however.

Although the findings were mixed, researchers say their pilot study should pave the way to larger clinical studies of cannabis as a treatment for sickle cell pain.

"These trial results show that vaporized cannabis appears to be generally safe," said Kalpna Gupta, PhD, a professor of medicine at UCI Irvine's Center for the Study of Cannabis. "They also suggest that sickle cell patients may be able to mitigate their pain with cannabis—and that cannabis might help society address the public health crisis related to opioids. Of course, we still need larger studies with more participants to give us a better picture of how cannabis could benefit people with chronic pain."

Opioid medication has been the primary treatment for sickle cell pain. But with many physicians now reluctant to prescribe opioids due to fears of addiction, overdose and government prosecution, sickle cell patients have been left with fewer options.

“In the current climate of increased awareness of the ongoing opioid epidemic, it would have been encouraging if this study had demonstrated decreased use of chronic analgesics during the active cannabis vaporization phase,” researchers concluded. “Our study’s small sample size and short duration may have contributed to the inability to demonstrate decreased opioid use among participants receiving the active drug compared with the placebo.”

Of the 33 U.S. states that have legalized medical cannabis, only four have included sickle cell disease as a qualifying condition. That forces many sickle cell patients to obtain cannabis from unapproved sources.

"Pain causes many people to turn to cannabis and is, in fact, the top reason that people cite for seeking cannabis from dispensaries," Gupta said. "We don't know if all forms of cannabis products will have a similar effect on chronic pain. Vaporized cannabis, which we employed, may be safer than other forms because lower amounts reach the body's circulation. This trial opens the door for testing different forms of medical cannabis to treat chronic pain."

A recent small study in Israel found that very low “microdoses” of inhaled THC can significantly reduce chronic pain in patients with neuropathy, radiculopathy, phantom limb pain or Complex Regional Pain Syndrome (CRPS).