Medical Cannabis Use Reduces Opioid Prescriptions in Patients With Osteoarthritis

Abstract

Background Osteoarthritis (OA) can result in significant pain, requiring pain management with opioids. Medical cannabis (MC) has the potential to be an alternative to opioids for chronic pain conditions. This study investigates whether MC used in the management of OA-related chronic pain can reduce opioid utilization. Methods Forty patients with chronic OA pain were certified for MC. Average morphine milligram equivalents (MME) per day of opioid prescriptions filled within the six months prior to MC certification was compared to that of the six months after. Visual analog scale (VAS) for pain and Global Health scores were measured at baseline, three, and six months post MC certification. Results Average MME/day decreased from 18.2 to 9.8 (n=40, p<0.05). The percentage of patients who dropped to 0 MME/day was 37.5%. VAS scores decreased significantly at three and six months, and Global Physical Health score increased significantly by three months. Conclusions MC reduces opioid prescription for patients with chronic OA pain and improves pain and quality of life.

Keywords: cannabis (marijuana); cannabis use; chronic pain management; opioid use; osteoarthritis (oa); prescription opioid.

Figure 1. Patients who filled controlled substance prescriptions within six months before medical cannabis certification

Of all patients with osteoarthritis (n=117), 48 were actively consuming opioids. Patients who had surgery within six months of medical cannabis certification (n=8) were excluded. Our final study population included 40 patients.

Figure 2. Opioid group shows decreased opioid prescriptions filled post medical cannabis certification

All patients on opioids showed a drop in morphine milligram equivalents per day (MME/day) from 18.2 to 9.8 (n=40, *p<0.05).

Figure 3. Pain and Quality of Life scores are improved following medical cannabis certification

Visual Analog Scale (VAS) pain score, Global Mental Health (GMH), and Global Physical Health (GPH) were measured at baseline (n=36) and at three months (n=26), and six months (n=16) following MC certification. VAS pain score decreased significantly from 6.6 at baseline to 5.0 (**p<0.01) at three months and 5.4 (*p<0.05) at six months (A). GMH increased insignificantly from 45.2 to 48.1 (p=0.17) at three months and 47.4 (p=0.42) at six months (B). GPH increased significantly from 37.5 to 41.4 (*p<0.05) at three months and increased insignificantly to 40.0 (p=0.18) at six months (B). MC: medical cannabis

Figure 4. Patterns of medical cannabis use

Patients were queried regarding patterns of MC use (n=21). When asked how often they take MC, 33.3% (n=7) said they take MC two to three times per day, followed by 19.0% (n=4) once a day, and 19.0% (n=4) three to four times a week (A). Among respondents who take multiple routes of MC (n=7), two patients take MC only during the day, three take MC only at night, and two take MC during the day and at night (B). MC: medical cannabis