A Study in Pain
There are relatively few well-controlled studies addressing the potential synergy of cannabinoids and opiates and whether or not cannabis can be used to reduce opioid dosing with relatively little risk. A study published this year in Nature in the category of neuropsychopharmacology, however, is a true well-designed, double-blinded, placebo-controlled study has clarified this question greatly.
The study, although small (N = 18), directly measured the effects of oxycodone alone at 2.5mg and 5mg, cannabis alone (smoked at 0% and 5.6% THC), and cannabis plus opiates on the sensation of pain by immersion of the hand in controlled cold water. In the study, 2.5mg of oxycodone was insufficient to change the times at which people sensed pain in cold water while 5mg significantly increased pain tolerance. It also showed that 2.5mg plus cannabis increased pain tolerance to the same amount as 5mg of oxycodone, showing clear synergistic effects.
This study also evaluated the risk of cannabis increasing oxycodone use and vice versa as well as the “likability” of oxycodone or cannabis when one plus the other was given. In this study, cannabis didn’t increase oxycodone use and oxycodone didn’t increase cannabis use (both significant). However, cannabis did increase the “likability” of oxycodone and thus the potential for increased opiate use with cannabis, at least in theory. So, although they did not see an actual increase in opiate use, we should consider the possibility. Smoked cannabis alone at the 5.6% THC level did not elicit an increased pain tolerance.
This study confirms through hard scientific analysis what we have seen in practice in states that have legalized cannabis. As the NPR article discusses, two studies show a 5.88-6.38% decrease in opiate prescriptions among medicaid patients and the other shows a decrease in total opiate doses by about 3.7 million (~14%) among Medicare Part D patients. This is in spite of the fact that opiate mortality has increased 320% from 2000 to 2015 in the nation.
The decrease in mortality alone justifies changing our national laws on cannabis and the Neuropharmacology study on pain directly confirms synergistic analgesic effects between cannabis and oxycodone with no increased risk of overuse. We finally need to take these studies seriously and take the scientific evidence at face value and change our laws to the benefit of patients in pain.