The study is comparing the use of inhaled delata-8-THC in the prevention of nausea and vomitting in patients being treated with moderately emetogenic chemotherapy, and the patients will continue use for 3 days afterward. Patients will be given rescue medication and will fill out VAS scales for nausea, pain, appetite and dizziness. Patients will be treated for 2 cycles, one cycle receiving active drug (one of 2 doses) and the other placebo. Patients receiving placebo will receive ondansetron injection before chemo and patients receiving active drug will receive a normal saline injection. Patients will take the drug 4 times daily for 3 days. The patients will return to clinic for a visit after 24-48 hours and 4 days. Patients will bring a urine sample to measure metabolite. Patients will be given a diary to monitor dosing and side effects as well as concomitant medication. The study will be conducted in 2 - 3 centers. There will be 108 patients enrolled with 27 in each of 4 groups: