Synergy between cannabidiol, cannabidiolic acid, and Δ⁹-tetrahydrocannabinol in the regulation of emesis in the Suncus murinus (house musk shrew).
Smoked marijuana contains over 100 different cannabinoids, including the psychoactive compound Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC, CBD, and its acidic precursor, cannabidiolic acid (CBDA), have all been shown to have antiemetic properties in the Suncus murinus (S. murinus house musk shrew). Here we show that when subthreshold antiemetic doses of CBD (2.5 mgkg ip) or CBDA (0.05 mgkg ip) are combined with a subthreshold antiemetic dose of THC (1 mgkg ip) in the S. murinus, both lithium-chloride-induced vomiting and abdominal retching are dramatically suppressed. These results suggest that combined effects of these compounds may lead to better control of vomiting with fewer side effects.