Cannabidiol may help prevent paclitaxel-induced peripheral neuropathy

Sep 26 2011

Cannabidiol—a compound derived from marijuana—may be a promising new treatment to prevent the development of painful neuropathy in patients receiving the chemotherapy drug paclitaxel, according to animal experiments reported in the October issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).

"Our preliminary findings…indicate that cannabidiol may prevent the development of paclitaxel-induced allodynia in mice and therefore be effective at preventing dose-limiting paclitaxel-induced peripheral neuropathy in humans," according to the report by Sara Jane Ward, Ph.D., and colleagues of Temple University School of Pharmacy, Philadelphia.

In Female Mice, Cannabidiol Reduces Paclitaxel-Induced Neuropathy

Paclitaxel—commonly used in the treatment of advanced breast or ovarian cancer—can cause nerve damage (neuropathy), leading to symptoms like pain, numbness, or tingling. Neuropathy is a potentially serious complication that can become "dose-limiting," preventing patients from receiving their full recommended course of chemotherapy.

Cannabidiol is a marijuana extract that has pain- and inflammation-reducing effects, while avoiding the psychoactive side effects of marijuana and other "cannabinoid" compounds. In previous studies, cannabidiol has shown promising effects in the treatment of neuropathic pain.

In the new study, male and female mice were treated with paclitaxel and monitored for evidence of neuropathy. The results showed that paclitaxel induced abnormal pain responses (allodynia) mainly in female mice—less so in males. Allodynia was more likely to develop at higher doses of paclitaxel.

When female mice were treated with cannabidiol before paclitaxel, it effectively prevented the development of allodynia. Abnormal pain responses to both cold and mechanical pressure were prevented by cannabidiol. The preventive effect was permanent, with no evidence that nerve damage developed after cannabidiol treatment was stopped.

Further Study Needed to Evaluate Cannabidiol's Effects in Humans

Painful neuropathy can result from a number of other causes besides paclitaxel, such as trauma or diabetes. Because neuropathy is difficult to treat, it's important to find effective ways of preventing it from developing in patients at risk.

Of course, the findings in animals are only preliminary. However, they support previous studies suggesting that cannabidiol reverses key inflammatory processes induced by paclitaxel—which could be involved in the development of nerve damage and abnormal pain responses.

The new results pave the way for studies to see if cannbidiol is useful in preventing neuropathy in human patients receiving paclitaxel. Dr. Ward and coauthors conclude, "Adjunct treatment with cannabidiol may be effective in the prevention or attenuation of paclitaxel-induced neuropathic pain and improve the outcomes for patients administered this chemotherapeutic drug."

"Cannabinoids are useful in many forms of pain relief," comments Dr. Steven L. Shafer of Columbia University, Editor-in-Chief of Anesthesia & Analgesia. "This study shows the utility of cannabidiol in a chronic pain model in mice. The results may have important applications to humans, provided they are reproducible."

Source: Anesthesia & Analgesia