Medical marijuana at odds with doctors' promise

Originally published in The Ottawa Citizen September 9, 2003
Original Title: Total Hyperbole and Coercion

Several of my patients have asked about the medicinal use of marijuana. Some are cancer patients, others have chronic pain syndromes. A conundrum exists; we must do our utmost to alleviate pain and suffering, adhere to an accepted standard of care based on scientific evidence and data and most importantly not harm the patient.

There is new evidence marijuana does help alleviate pain and combats the nausea and vomiting associated with chemotherapy. Other uses include slowing the progression of weight loss in AIDs and cancer sufferers, treating non-stop hiccoughs, glaucoma therapy, reduction of tremors and improvement of multiple sclerosis symptoms.

What has research uncovered about marijuana?

Tetrahydrocannabinol (THC), marijuana’s active ingredient, is a cannabinoid. Two known specific cannabinoid receptors or binding areas exist within the brain and central nervous system. The physical and psychological effects derive from THC binding to these receptors.

Intoxication occurs after the first few minutes of smoking marijuana and lasts about three to four hours. The physical effects include rapid heart and breathing rate, increased blood pressure, reddened eyes, dry mouth, increased appetite, impaired reaction time and immune system suppression.

Psychological effects include euphoria, a distorted sense of time, depression and/or anxiety, impaired short-term memory, paranoia and mystical thinking.

Users assume that after their high they are no longer under the influence of THC. Body fat accumulates marijuana and will continue to release THC over an extended time.

Recent evidence indicates thought processes, decision-making ability, judgment and coordination remain compromised 12 to 24 hours after the last joint. This impairment worsens with alcohol or other concomitant drug use. Evidence indicates that individuals who test positive for THC are more often involved in fatal traffic accidents.

Consistent and reproducible evidence indicates marijuana use does cause cognitive deficits lasting hours if not days after use. Research continues to look at whether this deficit persists with long-term use.

Marijuana is physically addictive. Stopping marijuana after 21 days of heavy use produces a withdrawal syndrome within ten hours of the last dose. The symptoms include irritability, agitation, depression, insomnia, nausea, loss of appetite and shakes. They peak in 48 hours and last about five to seven days.

The health risk is akin to tobacco smoking. Marijuana smoke’s tar content is four times greater than tobacco and contains 50 per cent more cancer causing chemicals (carcinogens). Marijuana and cigarette smoking technique differs: inhalation from a joint delivers almost twice as much smoke, inhalation time lasts one-third longer and breath-holding is four times longer than cigarette smoking.

Joints do not have filters. More particulate matter deposits throughout the upper airway and lung tissue. Continued use will reduce the smoker’s exercise capacity and cause chronic obstructive lung disease. Three to four joints per day produce the equivalent lung damage of 20 cigarettes per day as proven by microscopic (histological) evaluation of lung tissue.

Marijuana may reduce testosterone levels in men leading to impotence, impaired sex drive and breast development (gynecomastia). Infertility is a risk because of a reduction in sperm counts and sperm motility.

Chronic use in women can shorten menstrual cycles and stimulate the breast to produce and leak milk due to increases in the hormone prolactin. THC will accumulate in breastmilk and will enter the fetus’ bloodstream increasing the risk of low birth weight babies and abnormal newborn reflexes and responses.

Recent studies in the British Medical Journal and the American Journal of Psychiatry evaluated the relationship between marijuana use and the development of clinical depression/anxiety in teens. Indeed, daily smoking by young women had a five-fold increase in the odds of reporting depression and anxiety even when accounting for the use of other drugs.

There may indeed be subgroups of people who can tolerate frequent use of marijuana better than others. This argument is akin to the 95 year old chain-smoking grandmother outliving her family. Unfortunately, most of us do not have Grandma’s luck or genes.

The studies raise more questions than they answer. There are too many unknown variables and known serious consequences that increase the risk of patient harm contravening the “do no harm” tenet of medical care.

Marijuana’s legislated use as a prescription drug circumvents standard drug safety protocols and is not the standard of care. There is a safer drug alternative for some patients that mimics THC’s effects.

Cesamet (nabilone), a cannabinoid available in pill form, received approval to treat chemotherapy-induced nausea and vomiting in 1981. Its use extends to treating chronic pain syndromes. Its side effects (akin to marijuana) are reversible. It is not carcinogenic and does not cause the myriad of health problems associated with smoking marijuana. It may have applications for other medical conditions.

Most physicians will prescribe a drug that has been through thorough patient safety testing and clinical efficacy trials. Patients must choose their own treatment plan using all credible evidence. I and many other physicians choose not to prescribe marijuana for long-term chronic illness based upon this evidence. I cannot prescribe a medication that has the potential over years of use to cause more known harm and health complications in addition to the patient’s original condition. The government’s drug approval by fiat is unethical and does not follow Health Canada’s established medical standards.

© Dr. Barry Dworkin 2003

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