Study: Inhaled Cannabis Provides Long-Term Pain Relief and Reduces Opioid Use in Diabetic Neuropathy Patients

The five-year observational study followed 52 patients who had failed to respond to at least three conventional pain treatments, including opioids, gabapentin, and duloxetine. After a one-month washout period, patients began inhaling medical-grade cannabis containing 20% THC and less than 1% CBD. Assessments included pain scales, neuropathic symptom scores, blood sugar control, and medication use. By the end of the study, pain severity scores dropped from an average of 9.0 to 2.0, while pain interference scores fell from 7.5 to 2.2. Neuropathic symptom scores also improved, and patients reported sustained pain relief. Importantly, cannabis therapy was linked to better blood sugar control, with average HbA1c levels decreasing from 9.77% to 7.79%.

One of the most significant findings was a sharp reduction in the use of other medications. Patients lowered their morphine-equivalent opioid doses by over 90%, while gabapentin, duloxetine, and pregabalin use dropped by more than 75%. Researchers noted that cannabis dosage correlated strongly with both pain relief and reduced opioid use.

No serious adverse events occurred during the study. Mild side effects such as dry mouth and euphoria were reported in about 15% of participants, mostly during dose adjustments.

Researchers conclude the study by stating:

Inhaled cannabis add-on therapy mitigated symptoms of diabetic neuropathy over the course of a five-year observation period. Some reduction in glycosylated hemoglobin is observed as well as major reduction in the need for other prescription medications, including opiates and opioids. It is possible to state the following: (1). Inhaled cannabis significantly reduced pain and neuropathic symptoms over 5 years. (2). It decreased opioid use, supporting an opioid-sparing effect. (3). HbA1c improvements suggest a metabolic benefit, though causality is unproven. (4). No serious adverse events occurred, with mild effects in 15.4% of patients. (5). RCTs are needed to confirm efficacy and address accessibility barriers. Integration of objective pain assessment tools, such as salivary biomarker devices, could enhance the precision and reproducibility of cannabis therapy outcomes in DN.