Prolonged Medical Cannabis Treatment is Associated With Quality of Life Improvement and Reduction of Analgesic Medication Consumption in Chronic Pain Patients

Abstract

Introduction: Chronic non-cancer pain (CNCP) is one of the most prevalent indications for medical cannabis (MC) treatment globally. In this study, we investigated CNCP parameters in patients during prolonged MC treatment, and assessed the interrelation between CNCP parameters and the chemical composition of MC chemovar used. Methods: A cross-sectional questionnaire-based study was performed in one-month intervals for the duration of six months. Subjects were adult patients licensed for MC treatment who also reported a diagnosis of CNCP by a physician. Data included self-reported questionnaires. MC treatment features included administration route, cultivator, cultivar name and monthly dose. Comparison statistics were used to evaluate differences between the abovementioned parameters and the monthly MC chemovar doses at each time point. Results: 429, 150, 98, 71, 77 and 82 patients reported fully on their MC treatment regimens at six one-month intervals, respectively. Although pain intensities did not change during the study period, analgesic medication consumption rates decreased from 46 to 28% (p < 0.005) and good Quality of Life (QoL) rates increased from 49 to 62% (p < 0.05). These changes overlapped with increase in rates of (-)-Δ⁹-trans-tetrahydrocannabinol (THC) and α-pinene high dose consumption. Conclusion: Even though we observed that pain intensities did not improve during the study, QoL did improve and the rate of analgesic medication consumption decreased alongside with increasing rates of high dose THC and α-pinene consumption. Understanding MC treatment composition may shed light on its long-term effects.

Keywords: chronic pain; medical cannabis; phytocannabinoids; quality of life; terpenoids.

FIGURE 1

Pain intensity measures across study period. The median, inter quartile range, total range and outliers for the average, least and worst pain intensities are demonstrated for the study sample at one month intervals within a six-month period. VAS, Visual analogue scale; T₁, T₁-T₆, one to six months follow ups, respectively.

FIGURE 2

MC treatment measures across study period. The median, inter quartile range, total range and outliers for the monthly medical cannabis dose (A) and number of medical cannabis cultivars that are combined in a month period (B), displayed for the study sample at one month intervals within a six-month period. MC, Medical cannabis; g, grams; T₁-T₆, one to six months follow ups, respectively.

FIGURE 3

Cannabinoids and terpenoids relative dose in the consumed cultivars. The values in each box are the absolute concentrations of the specific phytocannabinoid (% w/w) or terpenoid (ppm) within each cultivar, and the color scale represents the z-scaled phytocannabinoid and terpenoid concentration variations between cultivars. *For each phytocannabinoid, the concentrations of the acid and its neutral counterpart were summed and reported as the total content; Method used: package "pheatmap", function pheatmap, with the (default): distance measure used in clustering rows "euclidean", clustering method used is "complete" on z scored data scaled by row; THC (-)-Δ9-trans-tetrahydrocannabinol; CBD, cannabidiol; CBC, cannabichromene; CBG, cannabigerol; CBN, cannabinol; THC-C4 (-)-Δ9-trans-tetrahydrocannabinol-C4; THCV (-)-Δ9-trans-tetrahydrocannabivarin.

FIGURE 4

Time-dependent outcome rates. The percentage of patients reporting on analgesics consumption and on 'better' quality of life, alongside with the percentage of patients consuming high THC and α-pinene monthly doses, demonstrated for the study sample at one month intervals within a six-month period. QoL, Quality of life; THC, ∆-9-tetrahydrocannabinol; T1, One-month Follow-Up; T2, Two month Follow-Up; T3, Three month Follow-Up; T4, Four month Follow-Up; T5, Five month Follow-Up; T6, Six month Follow-Up.

FIGURE 5

Predicted probabilities of analgesics consumption and quality of life by THC and α-pinene dose the predicted probabilities of the associations between the consumption of a high or low monthly doses of THC and α-pinene, separately (A,B) for analgesics consumption, (D,E) for 'better' quality of life) and by interaction (C) for analgesics consumption, (F) for 'better' quality of life). QoL, quality of life; THC, ∆9-trans-tetrahydrocannabinol; Low THC monthly dose refers to 123–4,892 mg, high THC monthly dose refers to 4,892–14,123 mg; Low α-Pinene monthly dose refers to 3,211–23,413 parts per million (PPM), high α-Pinene monthly dose refers to 23,413–471,725 PPM.

FIGURE 6

MC chemovar related quality of life reports Subgrouping of the consumed medical cannabis chemovars into low/high THC and α-pinene relative to patients' reports on 'better' quality of life. QoL, Quality of life; THC, ∆9-trans-tetrahydrocannabinol; MC, medical cannabis; Numbers on the bars represent the number of patients.