University of Texas researchers have discovered CBD and THC could be safe for use with opioid pain medicines and present a low-risk way to reduce opioid use among pain sufferers.
In an animal study, the team found the cannabinoids did not enhance the rewarding effects of opioids, meaning they may not increase the risk for addiction when used in conjunction with them.
The researchers gave rhesus monkeys the choice between a food reward or an injection of fentanyl. They then tested whether CBD, THC or a mixture of the two affected the number of times the monkeys chose fentanyl over food, and found a wide range of doses made no difference.
Lawrence Carey, postdoctoral fellow from the University of Texas Health Science Centre, said: “Giving the animals the opportunity to choose between a drug injection and a food reward helped us to somewhat replicate choices a human drug user may face, such as whether to spend money on drugs or food.”
“Having the option of responding for food is also useful for studying drugs like THC that produce sedative effects. It helps demonstrate the animal is reallocating behaviour from drug to food choice instead of simply shutting down response for a drug due to sedation.”
The researchers are conducting follow-up studies to test whether CBD and THC can reduce signs of opioid withdrawal and relapse.
According to Carey: “A big reason why people continue to take opioids after they become addicted is the appearance of withdrawal symptoms.
“We are using what we learned from this study to determine whether these doses — which didn’t alter choice for food or drug rewards — may help relieve opioid withdrawal or decrease relapse and drug-seeking behaviour following periods of abstinence.”
The researchers warned that before applying the findings to people, it will be necessary to determine whether the treatments alter other pathological processes involved with opioid use and to better understand any risks associated with their use.
Carey added: “There is intense interest in using medical marijuana in patients with chronic pain because compounds in marijuana like CBD and THC may produce pain relief themselves or enhance the pain-relieving effects of opioids.
“This means people could potentially use lower doses of opioids and still get relief from pain. Taking less pain medication could also lead to a lowered risk of addiction or physical dependence on opioids.”
