Overuse of medical cannabis may worsen pain

High-frequency use of cannabis appears to worsen clinical pain and associated symptoms among chronic pain patients, a recent study has found.

Researchers conducted a cross-sectional survey of 989 adults (mean age, 49.6±13.7 years; 59.0 percent female) who were using cannabis daily to ease their chronic pain. Outcomes included pain severity, pain interference, and associated quality of life measures, such as pain and anxiety. Light, moderate, and heavy use was defined as 1–2, 3–4, and ≥5 cannabis uses per day, respectively.

Of the participants, 531 reported only medical use of cannabis (MED), while 458 used it for medical and recreational purposes (MEDREC) in the past year.

Among MED adults, those who used cannabis lightly were more likely to take concomitant pain medications, though not opioids or benzodiazepines. However, pairwise analysis also found that light users had significantly lower pain severity scores compared to moderate or heavy cannabis users (5.4 vs 6.2 and 6.2; p<0.0001).

The same was true for pain interference, which was eased to a significantly greater degree in light users (4.4 vs 5.4 and 5.5; p<0.0001). Compared to heavy users, light MED users likewise had lower positive (p=0.037) and negative (p=0.011) affect.

The researchers also detected no such difference between frequency groups in MEDREC participants, except that light users reported worse physical function than moderate users (p=0.03).

“Our findings suggest that lower daily cannabis use frequency is associated with better clinical profile as well as safer use behaviours,” researchers said. “These trends highlight the need for developing cannabis use guidelines for clinicians to better protect patients using cannabis.”