Marijuana smoking associated with kidney damage.

The authors, Lambrecht et al, in Nephron, 70:494496, 1995, report on a 29-year-old man admitted to the hospital with severe pain in his back. He had smoked marijuana for 10 years, and just prior to admission had smoked several marijuana cigarettes and consumed several bottles of beer. No other psychotropic drugs were used. An area of damage in the right kidney resulting from a block in the major branch of the right kidney artery was detected. Toxicology screening on the urine revealed cannabinoids. All other causes of acute kidney infarction were excluded. The world's literature on cannabis effects on the kidney was reviewed by the authors.

Commentary: This report is the first one showing clotting off of an artery to the kidney resulting from acute marijuana smoking. The cardiovascular effects of marijuana are well-known and include dilation of peripheral blood vessels resulting in blood pressure changes and reflex, speeding up of the heart rate. If the heart rate is inadequate, there may be drops in blood flow to organs such as the kidney with resulting thrombosis of small arteries. Marijuana is known to be associated with myocardial infarction and stroke (Zachariah SB, Stroke 22:406-409, 1991; Charles et al. Clinical Toxicology 14:433-438, 1979). It is also possible that the marijuana damaged the blood vessels directly, as has been suggested for other drugs of abuse, such as amphetamines (Baden et al. New England Journal of Medicine, 284:111-113, 1971). It is clear from this case report, however, that a previously healthy male with acute ingestion of marijuana can clog the blood vessels of a major organ.

British study illuminates negative aspects of regular marijuana use.

A self-reporting study of the behavior of marijuana users attending a community drug and alcohol clinic was reported on by McBride in Drug and Alcohol Dependence 39:29-32, 1995. One hundred consecutive users were interviewed. All were Caucasian and 85% were male. The mean age was 28 and their cannabis use had been ongoing for approximately 12.5 years. No one in the sample was employed. All were receiving state benefits. Eighty percent smoked tobacco cigarettes as well. The author found that the average consumption of cannabis in the week preceding the interview was 10.5 grams with 60% of interviewees smoking daily. The average cannabis cigarette comprised 3 cigarette papers, the tobacco from three-quarters of a king-sized cigarette, and 0.35 grams of cannabis resin. Only 26% of the sample smoked tobacco in the absence of cannabis. Only 5% of the population took cannabis by oral ingestion. The amount of money spent on the cannabis averaged 35.00 or approximately $50.00 per week at current exchange rates. The author concluded that the high doses of cannabis used, the frequency of use, and the expenditure on the drug relative to income raised questions about the assumed benign effects of cannabis among those attending such clinics.

Commentary: Heavy use of cannabis was documented in patients attending drug and alcohol clinics for which cannabis was not the primary reason for referral to the clinic. Amphetamines, alcohol, opioids, and benzodiazepines comprised 94% of the cases referred. This data shows the frequency of cannabis use in combination with tobacco. This makes it very difficult to interpret self-reporting data about the health effects of tobacco alone. It is clear that drug-seeking behavior, even in patients undergoing treatment for drug and alcohol abuse, is not completely gone since other drugs are being used at the same time. Perhaps the difficulty in obtaining a higher level of treatment success relates to this fact. It is also startling to note the amount of money being spent on cannabis by a population supported by the government and in whom tremendous health care resources are being expended.

Marijuana cigarette triggers severe hyperthermia.

The symptoms of heatstroke include a body temperature of 104øF or greater, and delirium, coma, or seizures. Many drugs and chemicals have been associated with heatstroke, including amphetamines, cocaine, LSD, and PCP. Walter and associates, in Clinical Toxicology, 34:217-221, report a case of life-threatening hyperthermia associated with the use of marijuana alone. A 24 year-old man with a history of smoking one marijuana cigarette twice a month for many years left his office immediately after smoking one marijuana cigarette. He was acclimatized to the environment but had been jogging for only one week. The temperature was 84øF with a low relative humidity. He had no preexisting medical conditions. After jogging for 15 minutes, he became acutely ill and collapsed. Paramedics were called who noted a hot, red, dry skin and an agitated combative condition. They took him to an emergency department where his rectal temperature was recorded at 107øF. He required aggressive cooling and a tracheal tube for assisted breathing. It took him 16 hours to return to his usual mental state. All tests were negative except for urine and blood toxicology screens, which showed cannabinoids. No other drugs associated with hyperthermia were detected.

Commentary: This case report fits with animal studies and some human data showing that marijuana interferes with normal temperature control. In animal studies, marijuana has been shown to produce a condition known as poikilothermia, which is a loss of the ability to regulate temperature control. Marijuana is known to increase heat production in humans (Hanna et al. Aviation Space Environmental Medicine, 47:634-639, 1976, Rosenberg et al. Critical Care Medicine, 14:964-969, 1986). Thus, people who smoke marijuana in environments of high temperature and exert themselves are excessively predisposed to hyperthermia, which can be life threatening. The smoker feels less hot than they really are because of constriction of skin blood vessels and diminished sweating. The impaired ability to feel overheated produces a greater chance of developing heatstroke.

THC causes abnormalities in immune molecules

Zhu and colleagues continue a series of investigations into the mechanism of the immunological effects of the active ingredient in marijuana smoke, tetrahydrocannabinol (The Journal of Pharmacology and Experimental Therapeutics, 274:10011007, 1995). These authors had previously reported that interleukin 2, a potent substance released by activated immune cells (which are necessary for a proper immune response) is suppressed by ingredients in marijuana smoke. The current studies use a line of cloned natural killer cells of the immune system which are mixed with varying concentrations of THC. These cells were blocked in their ability to display this important molecule. The authors suggest that this effect may account in part, at least, for the THC suppression of the immune response.

Commentary: Further studies by the active immunology group of Klein, et al, at the University of South Florida, has further explained the way in which the active ingredient of marijuana can suppress the immune response. Somewhat surprisingly, the liberation of an important molecule by lymphocytes was not reduced, but instead, the place where it attaches on activated cells was suppressed. The result of this abnormality is that a cloned cell line of natural killer cells could not function in their ability to attack invading foreign molecules. Although these results are done in a test tube, it is frightening to think what the implications of this work is for patients already immunosuppressed by the viral disease, AIDS, where part of the viral infection is impairment of the immune system. Smoking marijuana in this setting would further depress the body's ability to fight those invading organisms which, ultimately, are the cause the death of most AIDS patients.

Rectal THC effective as an appetite stimulant

One potential use of delta-9 THC (dronabinol) is as an appetite stimulant in patients with cancer or AIDS. Mattes et al., Pharmacologic Pharmacology Biochemistry, and Behavior, 49:187-195, 1994, reviewed the subject of cannabinoids and appetite stimulation. They noted that most but not all prior studies showed marijuana to have some appetite stimulating property. In this study eleven subjects, all of whom were casual marijuana cigarette users, were observed. The authors compared oral THC with administration by a rectal suppository. Mean daily food intake was significantly increased when the patient was routinely using the rectal suppository, but this did not occur with either an oral capsule or dissolving an oral dose under the tongue.

Commentary: This study confirms the efficacy of rectal suppositories in appetite stimulation. The drug absorption from the rectal suppository was adequate to accomplish the therapeutic goal compared to oral or inhalation routes. There was no correlation between drug efficacy and the age, gender, the drug "high" or plasma drug levels. This study further supports the possibility of developing a rectal suppository form of delta-9 THC for use in appetite stimulation in chronically ill patients.

Material used in this publication has been reviewed and commented on by William M Bennett, M.D., Professor of Medicine, Division of Nephrology, Clinical Pharmacology and Hypertension at Oregon Health Sciences University, Portland, Oregon. Drug Watch Oregon, P.O. Box 5853, Portland, Oregon, 97228-5853.