Research into the medical benefits of marijuana has been somewhat held back due to its federal status as a schedule 1 controlled substance, and the limited availability of research-grade marijuana. As of 2008, however, the distinguished American College of Physicians have announced their official support for additional scientific research into medical marijuana and have released an official document outlining their position. Such positive developments have owed much too the conclusions drawn by the Institute of Medicine (IOM), when in 1997 they were asked by the White House Office of National Drug Control Policy to review the scientific evidence for the therapeutic properties of medical marijuana and assess the risks and benefits of its use. The IOM, after an extensive review, concluded that marijuana did indeed have therapeutic properties and could potentially be utilized in the treatment of a wide variety of illness. Since the publication of this report, scientific research into the therapeutic qualities of medical marijuana has increased in both number and quality.
Amusingly, marijuana had a long history of being an accepted medicine in the United States before its criminalization. It was included in the U.S. pharmacopoeia until 1942 when it was removed due to its new federal status as an illegal drug.
Contemporary Scientific and Medical Studies on Marijuana:
There have been a number of studies dedicated to the efficacy of marijuana s effect in the treatment of nausea and on its utility in stimulating the appetite. Clinical trials have shown that the use of marijuana encouraged the appetite, increased caloric intake, and allowed for significant weight-gain in patients suffering from hiv related wasting. (2) In studies focused on patients undergoing chemotherapy, marijuana was found to be equivalent and sometimes superior in symptom relief to well-known anti-nausea drugs such as metoclopramide.(2) In the treatment of nausea, research has also led to the conclusion that the combination of THC and a standard anti-nausea drug was more powerful in effect than either one when used alone.
Studies have shown that cannabanoids can reduce high introcular pressure by up to 25% after the ingestion or smoking of cannabis products. In order to reduce ocular pressure however high amounts of THC ingestion are necessary, and the effects are fairly short lived. There is also concern that the hypotensive effects of cannabis may in the long term lead to reduced blood flow to the optic nerve. Because of this, and the potential issue of adverse interactions with antiglaucoma drugs, patients using medical marijuana in the treatment of glaucoma should consult with an ophthamologist about their marijuana usage and any possible interactions it might have with any pharmaceuticals they may be taking for this condition.
Multiple Sclerosis, Spinal Cord Injuries, Neuropathy and other movement based disorders:
Cannabonoids have a significant anti-inflammatory effect, and have been found to inhibit smooth muscle contractions, making them powerful anticonvulsants. The use of marijuana has been shown in many clinical trials to provide relief from spasticity, pain, and tremors in patients with multiple sclerosis, spinal cord injuries, and other trauma. In a recent study of patients suffering from HIV- related sensory neuropathy, the consumption of cannabis resulted in a 17% decrease of symptoms over the placebo group.
Research into the use of medical marijuana for pain-related conditions has been very hopeful. Amongst cancer patients oral doses of THC have led to the reduction of pain on a level comparable to that of codeine usage. In fact 20mg of THC was approximately as effective as 120 mg of codeine in the treatment of pain related to advanced cancer. In a fascinating article Marijuana produced changes in Pain Tolerance: Experienced and non-experience Subjects published in the journal International Pharmopsychiatry, medical researchers found that the analgesic effect of cannabis usage was more prominent in experienced users. In other words, long term users of cannabis experienced a more pronounced analgesic effect then those patients who used cannabis less commonly.