Medicinal cannabis can safely ease cancer pain while cutting patients' reliance on opioids and other medications, according to Canadian researchers, with THC:CBD-balanced products proving especially beneficial.
The research team examined treatment outcomes for 358 adult cancer patients whose data had been submitted to the Quebec Cannabis Registry in Canada between May 2015 and October 2018.
Participants had an average age of 57 and were almost evenly split by gender. The three most prevalent cancer types among them were genitourinary, breast, and bowel cancers. Pain was the most commonly cited reason for a medicinal cannabis prescription, affecting 72.5% of patients.
THC-dominant products were authorised for 24.5% of patients, THC:CBD-balanced products for 38%, and CBD-dominant products for 16.5%. Oral administration was the most frequently recommended method, accounting for 59% of cases.
Researchers tracked pain intensity, symptoms, total medication count, and daily morphine consumption at three-month intervals over the course of one year.
Pain intensity was assessed using validated tools on a scale from no pain (0) to the worst imaginable (10), while pain relief was rated from none (0%) to complete (100%). Two composite measures captured overall pain severity and the degree to which pain interfered with daily life in the preceding 24 hours.
Medicinal cannabis appeared safe and well tolerated throughout the study. Only 11 patients reported a combined total of 15 moderate to severe side effects, 13 of which were classified as minor. Drowsiness, noted by three patients, and fatigue, reported by two, were the most frequently occurring adverse effects.
Two serious side effects — pneumonia and a cardiovascular event — were considered unlikely to be connected to medicinal cannabis use. Just five patients discontinued treatment due to side effects.
Statistically significant reductions in worst and average pain intensity, overall pain severity, and pain interference with daily life were recorded at the three-, six-, and nine-month check-ins.
Across the patient group, THC:CBD-balanced products were associated with greater pain relief compared to both THC-dominant and CBD-dominant formulations.
The total number of medications patients were taking declined steadily at every quarterly review, and opioid consumption dropped across the first three follow-up intervals.
Based on these findings from the observational study, the researchers concluded: "Our data suggests a role for [medicinal cannabis] as a safe and complementary treatment option in patients with cancer failing to reach adequate pain relief through conventional analgesics, such as opioids."