USA — Sue was dying of cancer. She was thin, her skin was gray, and she hadn’t eaten much in several days.
Offered a medication to relieve some of her symptoms, she reluctantly accepted. Within five minutes of taking this medication, she again had color in her cheeks, was laughing with friends and asking for a fruit smoothie. It was the first of several she would request that day and her grateful husband was only too glad to oblige. What was this miracle drug?
What many call marijuana, pot, or weed, the medical community calls cannabis. Cannabis contains approximately 70 different active ingredients called cannabinoids, only a few of which are psychoactive.
THC (tetrahydrocannabinol) is the most well-known psychoactive cannabinoid, and due to years of breeding, THC currently accounts for up to 25 percent of the total weight of the prepared herb.
Another well-known cannabinoid is CBD (cannabidiol), which is not psychoactive but currently represents only about 0.5 percent of the herbal weight. In many well-designed scientific studies, these and other cannabinoids appear to be therapeutic.
The 1999 Institute of Medicine Report clearly stated that “accumulated data indicate a potential therapeutic value for cannabinoid drugs, particularly in the areas of pain relief, control of nausea and vomiting and appetite stimulation.” Research in the past 10 years has revealed much more.
The International Cannabinoid Research Society held its 19th annual symposium in St. Charles, Ill., in July, sponsored by the NIH, the National Institute on Drug Abuse and several pharmaceutical companies, among others. This symposium brought together reputable scientists from 25 nations and over 100 research labs to share new findings. These researchers have long recognized the use of cannabinoids for a wide array of symptoms that include nausea and vomiting, pain management, muscle spasticity, anxiety, depression, post-traumatic stress syndrome, inflammatory bowel disease and insomnia.
Cannabinoids are naturally recognized in the bodies of animal species all the way down to invertebrates. In humans, CB1 receptors are found in the brain, and CB2 receptors are found throughout the immune system. These receptors couple with the body’s own internally produced cannabinoids, in addition to coupling with inhaled or ingested cannabis.
Startling news about cancer and cannabinoids was recently published by Donald Abrams, MD, Chief of Hematology-Oncology at San Francisco General Hospital and Manuel Guzman, PhD, Professor of Biochemistry and Molecular Biology at Complutense University in Madrid, Spain. These experts found that cannabinoids inhibit tumor growth and also appear to specifically kill tumor cells without affecting cells that are still healthy. Tumor cells that have been shown to be sensitive to cannabinoid-induced growth inhibition include leukemia/lymphoma, skin, uterus, and breast, gastric, colorectal, pancreatic and prostate carcinomas.
The safety profile of cannabinoids is impressive: unlike opiates, cannabinoids do not affect areas in the brain that control breathing. The lethal (LD50) dose of inhaled cannabis has been estimated to be 1,500 pounds smoked in 15 minutes. The psychoactive qualities of THC limit effective medicinal use in many patients, so development of strains that contain less THC and more CBD is being encouraged. It does appear that whole-plant use is more effective than isolating and using any single cannabinoid.
Even used medicinally, cannabis comes with some cautionary advice. The psychoactive effects are not necessarily welcomed, and the patient must consider local laws when traveling outside tolerant states such as California. Inhaling the herb smoke can cause irritation of the airways, although there has been no evidence to date that cannabis increases the incidence of respiratory cancer.
The two most commonly used methods of delivery are inhalation and ingestion.
Inhaled, cannabinoids enter the lungs, the circulatory system, and then quickly find their way to receptors. Peak levels are reached in about five minutes, and in one hour most have been metabolized. The effects are rapid, and frequent re-dosing is necessary for symptom control.
Ingested, the substance first goes to the liver where it is metabolized into 11-hydroxy-THC, a substance much more psychoactive than the original THC. Peak levels are reached in about one hour and are sustained for about four hours. Steady-state levels are easier to achieve with oral ingestion, but the psychoactive side effects may limit acceptable oral use. In the U.S., the non-psychoactive CBD cannabinoid in tablet or liquid form is not yet available.
Research is starting to show cannabis to be a safe, effective and powerful medicine, with the health benefits outweighing risks. Further research is needed to explore the potential of this medicine, but its ability to heal should not be underestimated.
* Review of current research findings: http://norml.org/index.cfm?Group_ID=7002
* O’Shaughnessy’s — The Journal of Cannabis in Clinical Practice: http://www.PCMD4U.org/
Dr. Stacey Kerr, a longtime Sonoma County family physician, graduated from UC Davis Medical School and is certified in her specialty by the American Board of Family Medicine. Her columns are not intended as a substitute for hands-on medical advice or treatment. Consult your health care provider before adhering to any recommendations in this column.
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