Medical marijuana markets are growing fastest in Oklahoma and Florida, studies show, prompting calls for research on health impacts and drug interactions.
Medical marijuana is legally available in 36 states and Washington, D.C., while 11 states have moved to legalize recreational marijuana. One national expert said the structure of the laws in each state determines how quickly medical marijuana gains popularity.
"In Oklahoma, you had rapid implementation of the law after voters approved," said Karen O'Keefe, director of state policies for the Marijuana Policy Project, a nonprofit national organization. "In Florida, the state was a little slower to move, and the growth of the industry is slower. There are also more restrictions in Florida."
O'Keefe said Oklahoma's fast pace resulted in a lack of testing for the safety of the cannabis sold to patients. After calls for reform, that was corrected.
Growth in Oklahoma is powered by "low barriers of entry, including the fact there's no list of qualifying conditions for patients," a recent report from Marijuana Business Daily said. It said the registered patients in Oklahoma now make up 4.1 percent of the population. In Florida, registered patients represented 1.6 percent of the state's total population.
Florida's medical marijuana industry is growing so fast that state legislators and scientists from the University of Florida worry about best practices for use.
"Drug interactions are really under-studied," said Robert Cook, a University of Florida professor and director of clinical research for the state's Marijuana Research Consortium. "A lot of people in Florida are older, they're on a lot of meds.
Cook said researchers want to learn if medical marijuana actually helps to reduce dependence on opioids. "We really need these studies," he said.
On Monday, the research consortium adopted a plan for its first year. It intends to create a database of patients to track outcomes from the use of medical marijuana.
"There are several hundred thousand people registered to get medical marijuana in Florida now, and the state wants to understand safety, especially," Cook said.
The University of Florida is to receive $1.5 million annually in state funding for the effort. Cook said $600,000 of that will go to research projects by various competing Florida schools that apply for funding.
One are of concern is whether potential benefits of smoking marijuana are negated by damage to the lungs and other health issues. Smoking medical marijuana in Florida was made legal in March, two years after voters approved it.
When the state's Amendment 2 passed, it specified the conditions for which medical marijuana could be used. They included cancer, epilepsy, glaucoma, HIV-positive status, AIDs, post-traumatic stress disorder, ALS, Crohn's disease, Parkinson's disease, multiple sclerosis, chronic pain and terminal illness.
"In Oklahoma, patients just need a doctor's recommendation, and there's not a list of qualified medical conditions," O'Keefe said.