Cannabis terpenes may relieve chemotherapy-induced neuropathic pain

By Dr. Tim Sandle
May 29, 2024

Germany will now have some of the most liberal cannabis laws in Europe - Copyright AFP/File John MACDOUGALL

A new study from University of Arizona Health Sciences finds that Cannabis sativa terpenes are as effective as morphine at reducing chronic neuropathic pain. Furthermore, the results indicated that a combination of the two analgesics further enhanced pain relief without leading to negative side effects.

While prior studies have shown that the Cannabis sativa plant along with its two primary cannabinoids – tetrahydrocannabinol and cannabidiol – can be effective in managing chronic pain, the results were considered to be generally moderate. In addition, these earlier studies had flagged concern with unwanted psychoactive side effects.

In contrast, terpenes, the compounds that give plants their aroma and taste. These compounds offer an alternative path to pain relief without adverse side effects. Cannabis is unique in that it contains up to 150 terpenes with multiple terpenes acting as the dominant species.

Discussing the research, lead scientist John Streicher says: “A question that we’ve been very interested in is could terpenes be used to manage chronic pain?…What we found is that terpenes are really good at relieving a specific type of chronic pain with side effects that are low and manageable.”

Streicher tested five terpenes that are found in moderate to high levels in Cannabis: alpha-humulene, beta-caryophyllene, beta-pinene, geraniol and linalool. It had earlier been established that four of those terpenes mimicked the effects of cannabinoids, including a reduction in the sensation of pain, in animal models of acute pain.

For the new research, the scientists used a mouse model of chemotherapy-induced neuropathic pain, a type of chronic pain that occurs when highly toxic chemotherapy medications cause nerve damage that results in pain.

The terpenes were tested individually and then compared with morphine. It was found that each terpene was successful in reducing the sensation of pain at levels near to or above the peak effect of morphine.

Furthermore, when the terpenes were combined with morphine, the pain-relieving effects of all five terpene/morphine combinations were significantly increased.

Unlike opioids, none of the terpenes had reward liability, making them a low risk for addiction. Some of the terpenes also did not cause aversive behaviours.

The research appears in the journal Pain, titled “Terpenes from Cannabis sativa induce antinociception in a mouse model of chronic neuropathic pain via activation of adenosine A2A receptors.”