A therapeutic method and composition which includes a cannabinoid chemically linked to a chemotherapy agent. The therapeutic composition is capable of crossing the blood-brain barrier, and delivery of the composition across the blood-brain barrier provides both chemotherapy for the treatment of brain cancer and alleviation of side effects caused by the chemotherapy agent. Once across the blood-brain barrier, the chemotherapy agent will be released to attack cancer cells, and the cannabinoid will be free to bind to cannabinoid receptors in the brain to alleviate side effects of chemotherapy such as nausea/vomiting, pain and decreased appetite.