Ariana Brice-Tutt
University of Florida
Co-authors: Wendi Malphurs1, Robert M. Caudle1, Marcelo Febo1, Barry Setlow1, Niall P Murphy1, John Neubert1
1University of Florida
Objective: Investigate the effect of chronic oxycodone and cannabidiol treatment, alone or in combination, on behavior using an operant orofacial reward-pain conflict model.
Methods: Using the orofacial pain assessment device (OPAD) rats were trained to consume a positive reinforcer of a sweetened condensed milk solution under nociceptive (44.5°C) and non-nociceptive (37°C) conditions. We then investigated the effect of chronic oxycodone (0.56 mg/kg, i.p.) and cannabidiol (3.2 and 10 mg/kg, i.p.) treatment, alone or in combination, on operant responding at the different temperatures over 14 days of treatment.
Results: Oxycodone increased responding under both thermal conditions. Neither dose of cannabidiol administered alone altered responding but when combined with oxycodone, cannabidiol dose-dependently increased responding beyond that produced by oxycodone alone. This action was more efficacious at the higher temperature, suggestive of a largely analgesic effect.
Conclusions: These results suggest that while being devoid of any inherent activity, cannabidiol may potentiate the analgesic effect of oxycodone. As such, cannabidiol may be useful as an opioid-sparing approach to treating pain. Future work will further investigate oxycodone and cannabidiol interactions, particularly in the context of oxycodone reinforcement and reward.