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 mg/kg ip) or CBDA (0.05 mg/kg ip) are combined with a subthreshold antiemetic dose of THC (1 mg/kg 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.