Pubdate: Mon, 16 Dec 2002 Source: Report Magazine (CN AB) Copyright: 2002 Report Magazine, United Western Comm Ltd Contact: http://www.report.ca/ Details: http://www.mapinc.org/media/1327 Author: Joanne Byfield BAD NEWS FOR POT SMOKERS Ounce for ounce, a British study says, marijuana does more damage than tobacco Since former federal Health minister Alan Rock approved the use of marijuana for "grave and debilitating" illnesses in July 2001, the Office of Cannabis Medical Access has issued 432 authorizations to individuals. Health Canada warns them that it has not tested or approved the use of marijuana "for its safety, efficacy and quality." In fact, it's not safe according to a review of scientific evidence on cannabis smoking and respiratory ailments by the British Lung Foundation. The BLF study, released in November, reported that today's marijuana joint contains an average of 150 milligrams of tetrahydrocanabinol (THC), the psychoactive and pain-relieving element, compared to 10 mg in the 1960s. That difference may negate longitudinal studies based on users from the '60s, says the BLF. Smoking three to four joints a day produces acute and chronic bronchitis comparable to 20 or more cigarettes. One possible reason: potheads inhale more deeply and hold the smoke in their lungs longer than nicotine addicts. The BLF study also noted that research remains inconclusive on the link between pot smoking and chronic obstructive pulmonary disease and respiratory cancer. The Canadian Medical Association (CMA) opposes the medical use of marijuana without solid scientific evidence and further rigorous testing. CMA President Dana Hanson says doctors are in a tough position. "We don't know the harmful effects of this drug, we don't know how it interacts with other medications and we don't have any scientific evidence about its effectiveness. So why are we proceeding with it?" The CMA supports further research, but it must be as rigorous and thorough as for any other drug. The only peer-reviewed clinical trial approved by the federal government is at the McGill Pain Centre. Mark Ware will conduct a pilot project on 30 patients. They will receive therapeutic doses of standardized and homogeneous cannabis for five days to study its effectiveness for controlling pain. "Most of the scientific studies have been done on recreational users," says Dr. Ware. This study will use cannabis produced by the U.S. government. Smoked cannabis has a different effect than THC taken orally. The oral drug takes about an hour-and-a-half to be absorbed into the liver, and absorption changes the drug. Inhaling the smoke provides immediate delivery into the bloodstream, more like intravenous. The pilot study will report on all the side effects, as well as pain relief. Most drugs have side effects, Dr. Ware says. For instance, "Advil can cause gastric problems, but the risk is acceptable because of its ability to reduce pain." If his pilot shows that marijuana is an effective short-term pain reliever, a larger, longer-term study will follow. The McGill researcher thinks pot should be approved for terminal patients if it is the most effective pain reliever. Non-terminal patients may have to wait for more investigation into side effects, he suggests: "I don't think a doctor would use a drug approved for short-term pain relief, for a long-term use."