An increasing number of people in Florida are choosing medical cannabis over opioids to treat pain relief, according to the boss of the state's first and largest fully licensed medical marijuana company. "We're seeing a huge transition," Kim Rivers, CEO of Trulieve Cannabis Corp. (TCNNF), told CNBC in an interview. Trulieve, which recently listed its shares on the Canadian Securities Exchange, cultivates, manufactures and distributes 90 cannabis-based products in 17 retail locations across the state of Florida.