A study by researchers at the University of California shows that cannabis may have the potential to treat the chronic pain associated with sickle cell disease. Results of the research, which was led by University of California at Irvine researcher Kalpna Gupta and Dr. Donald Abrams of U.C. San Francisco, were published last week in the journal Jama Open Network.

“These trial results show that vaporized cannabis appears to be generally safe,” said Gupta, a professor of medicine on the faculty of UCI’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.”

To conduct the randomized, double-blind, placebo-controlled study, 23 patients with sickle cell disease participated in two five-day inpatient sessions during which they inhaled either vaporized cannabis or a vaporized placebo. The two sessions were held at least 30 days apart so each participant could act as their own control group by completing one session with cannabis and one session with the placebo. Patients also used opioid painkillers during the study.

The cannabis used in the trial contained 4.4% THC and 4.9% CBD. Researchers assessed the participants’ pain levels throughout the treatment period and determined that cannabis’ effectiveness in reducing pain appeared to increase over time. As the five-day study period progressed, participants reported that their pain interfered with activities including walking and sleeping. Researchers also noticed a statistically significant reduction in how severely subjects’ pain affected their mood.

Blood Disorder Causes Severe Pain

Sickle cell disease is a group of blood disorders characterized by abnormal hemoglobin molecules that result in sickle-shaped red blood cells. Sickle cell disease can lead to obstructions of blood flow that cause chronic discomfort and episodes of severe pain commonly treated with opioids, which can be dangerously addictive and have other health risks. A 2018 study by Yale New Haven Hospital and Yale University found that patients with sickle cell disease often turn to marijuana for pain relief.

“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 of the new research. “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.”

The study showed that the reduction in pain after vaporizing cannabis did not rise to the level of a statistically significant decrease. However, cannabis did relieve the pain of the patients who received it and performed better than the placebo, leading researchers to call for further study.

“Inhaled cannabis appears to be safe when used in conjunction with opioids and better than placebo at reducing pain,” Abrams said.