In March, several bills were introduced, the most ambitious a measure that would let states legalize marijuana for medical use without federal interference. Another bill would exclude Charlotte's Web from the list of controlled substances. Other measures would limit federal prosecutors' power to go after growers, vendors and users who obey state laws.
Meantime, as people like Gorman testify to the plant's effects, medical marijuana is rapidly becoming a go-to treatment for hundreds of thousands of patients for whom conventional treatments have failed. This is true despite the fact that research into the plant's benefits is worryingly thin. A sweeping review of the research done so far, published in the Journal of the American Medical Association in June, found that most studies have produced, at best, only "moderately" trustworthy evidence of effectiveness, mostly in patients undergoing cancer chemotherapy, people suffering chronic pain, and multiple sclerosis patients with pain and spasticity. The evidence was "poor" for many state-approved indications, such as hepatitis C, Crohn's disease, Parkinson's disease and Tourette syndrome, wrote psychiatrists Deepak Cyril D'Souza and Mohini Ranganathan of the Yale University School of Medicine in an accompanying editorial. Research on seizures is going on now. On the other hand, cannabis contains a potential pharmacopeia of more than 80 chemicals called cannabinoids and approximately 400 other compounds. "I do believe if we did the appropriate research, we would find some of those compounds have true medicinal value," says Otis Brawley, chief medical officer of the American Cancer Society.
The cannabinoid responsible for marijuana's mind-altering properties, delta-9-tetrahydrocannabinol or THC, was identified in the early 1960s along with the active ingredient in Charlotte's Web, cannabidiol, which lacks THC's trippy high. One explanation for medical marijuana's broad biological activity is that humans, like all other creatures, have innate cannabinoids that bind to receptors in the brain and immune system and play a critical role in growth and development, scientists say. Research in animals shows that if you block cannabinoid receptors in infancy, the animals will stop eating and die.
The receptors' location may offer clues to cannabinoids' perceived medical effects. One set of receptors is concentrated in nerve centers linked to pain perception, for example; a second set, mainly found in the immune system, may account for cannabis' potent -- and well-established -- anti-inflammatory properties. Scientists have found that cannabinoids act as a nervous system dimmer switch, slowing or blocking signals between nerve cells.
High concentrations of signal-blocking cannabinoid receptors throughout the brain may explain why cannabinoids appear to quell seizures. Receptors are similarly dense in regions that control movement, promote appetite and combat nausea, which may explain why marijuana seems to relieve muscle spasticity and boost appetite. Although cannabis has many side effects -- dry mouth, bloodshot eyes, inceased appetite, diminished short-term memory, anxiety and impaired reaction time among them -- no fatal overdose has ever been reported. That's likely due to the relative absence of cannabinoid receptors in the brain stem, the region that controls heart rate and breathing.
Some researchers believe that cannabinoids may actually treat cancer itself. In the lab, they stop cells from dividing and slow the spread of cancer cells into nearby tissues. And researchers in Spain and England have shown that cannabinoids can shrink brain tumors in animals. "Our animal work is very convincing indeed," says Stephen Wright, chief medical officer of GW Pharmaceuticals, a British firm that is developing cannabis-derived drugs. The company is now studying a drug in patients with recurrent brain cancer, Wright says, with results due next year.
Beyond the plant extracts, two drugs that are synthetic versions of THC, Marinol and Cesamet, are available by prescription across the U.S. Both were approved in 1985 to relieve nausea and vomiting in cancer patients. Marinol also has been shown to combat weight loss in people with HIV/AIDS. In addition, GW Pharmaceuticals has three pharmaceutical-grade cannabis medicines, including one, still unnamed, that is being tested in patients with Type 2 diabetes. Sativex, a mix of cannabidiol and THC, is approved in 28 countries for relieving spasticity and is being tested in the U.S. for its ability to relieve cancer pain.
The third drug, Epidiolex, made of cannabidiol only, is being tested in
children with severe epilepsy whose seizures haven't responded to other
drugs. Preliminary results in more than 130 children revealed that
after 24 weeks of treatment, their average number of seizures had fallen
by 45 percent, says neurologist Orrin Devinsky, director of the NYU
Langone Comprehensive Epilepsy Center, who is leading the trial. In
Colorado, neurologist Edward Maa, chief of the Comprehensive Epilepsy
Program at Denver Health Medical Center, is taking advantage of the
community using Charlotte's Web to closely monitor the experience of 150
seizure patients.
Maddie,
now 8, is rapidly making the headway she couldn't when constantly
having seizures. "She knows her ABCs now. She knows her colors and her
shapes," says Gorman. "We plan to begin working on sight-words this
summe
Comments
Post a Comment