Neuropathic pain from oxaliplatin-based chemotherapy regimens occurs in up to 90% of patients, and continued exposure to the regimen leads to chronic neuropathy in 31% of patients. Now, researchers from Tel Aviv, Israel, have found that cannabis use may be effective in reducing neuropathic pain brought on by chemotherapy.
Oxaliplatin is a platinum-based chemotherapy commonly used to treat gastrointestinal malignancies. When used with other medicines such as fluorouracil and leucovorin, it is also used to treat advanced colorectal cancer.
For the study, the researchers examined 513 patients who were treated with oxaliplatin and 5-fluorouracil-based chemotherapy regimens. The patients were split into two groups- one treated with cannabis and the other treated without. Of the patients treated with cannabis, 116 received cannabis before their chemotherapy regimen, while 132 patients received cannabis afterward.
All in all, the researchers found that rates of neuropathy from chemotherapy were reduced among patients treated with both cannabis and oxaliplatin when compared to controls. In particular, however, they noted that the reduction was more significant among those who received cannabis before chemotherapy than during.
While 75% of those who received cannabis prior to chemotherapy no longer experienced neuropathic pain, the same was true for just 46.2% of those who took cannabis after starting chemotherapy. This discrepancy suggests that cannabis may have a protective effect against neuropathic pain from chemotherapy.
While interesting results, the researchers say that their conclusions have some limitations. For example, they were unable to compare the amount of licensed cannabis or types and indications for its use. Moreover, neuropathy was assessed retrospectively and relied on doctors' records of patients' complaints and physical examinations. As such, to make their results more robust, the researchers have now planned a larger trial to study the same mechanism.