ABSTRACT
The first study comparing oral Δ9-tetrahydrocannabinol (THC) to placebo capsules and marijuana to marijuana placebo cigarettes was published by Chang et al. (1979). In this study 15 patients were given oral doses of THC over several courses of chemotherapy. Each subject received a 10 mg THC capsule beginning two hours prior to chemotherapy and every three hours subsequently. In the event of a breakthrough vomiting episode, those patients were given marijuana cigarettes to smoke for the remaining administrations rather than oral THC. When measured THC blood levels were < 5 ng/mL, 44 percent of subjects vomited, between 5 ng/mL and 10 ng/mL, 21 percent vomited, and > 10 ng/mL, 6 percent vomited. After smoking marijuana, the incidence of vomiting for the same blood levels ranges were 83 percent, 38 percent and 0 percent. Vomiting rates after placebo capsules or smoked placebo marijuana were 72 percent and 96 percent, respectively.
