Background: Our aim was to determine the combined and independent effects of tobacco and marijuana smoking on respiratory symptoms and chronic obstructive pulmonary disease (COPD) in the general population. Method: We surveyed a random sample of 878 people aged 40 years or older living in Vancouver, Canada, about their respiratory history and their history of tobacco and marijuana smoking. We performed spirometric testing before and after administration of 200 μg of salbutamol. We examined the association between tobacco and marijuana smoking and COPD. Results: The prevalence of a history of smoking in this sample was 45.5% (95% confidence interval [CI] 42.2%–48.8%) for marijuana use...

Background. Marijuana smoking is common and believed to relieve many symptoms, but daily use has been associated with liver fibrosis in cross-sectional studies. We aimed to estimate the effect of marijuana smoking on liver disease progression in a Canadian prospective multicenter cohort of human immunodeficiency virus/hepatitis C virus (HIV/HCV) coinfected persons. Methods. Data were analyzed for 690 HCV polymerase chain reaction positive (PCR-positive) individuals without significant fibrosis or end-stage liver disease (ESLD) at baseline. Time-updated Cox Proportional Hazards models were used to assess the association between the average number of joints smoked/week and progression to significant liver fibrosis (APRI ≥ 1.5), cirrhosis (APRI ≥...

Background: Despite several lines of evidence suggesting the biological plausibility of marijuana being carcinogenic, epidemiologic findings are inconsistent. We conducted a population-based case-control study of the association between marijuana use and the risk of lung and upper aerodigestive tract cancers in Los Angeles. Methods: Our study included 1,212 incident cancer cases and 1,040 cancer-free controls matched to cases on age, gender, and neighborhood. Subjects were interviewed with a standardized questionnaire. The cumulative use of marijuana was expressed in joint-years, where 1 joint-year is equivalent to smoking one joint per day for 1 year. Results: Although using marijuana for z30 joint-years was positively associated in...

Concern exists that liver transplant center substance abuse policies may have an inappropriate and disproportionate impact on marijuana users. Our hypothesis is that patients with chronic liver disease who were marijuana users will have inferior survival. This is a retrospective (1999–2007) cohort study. The primary outcome measure is time-dependent, adjusted patient survival from the time of liver transplant evaluation. The primary exposure variable is a positive cannabinoid toxicology screen during the liver transplant evaluation period. Overall, 155 patients qualified as marijuana users while 1334 patients were marijuana non-users. Marijuana users were significantly (p < 0.05) younger (48.3 vs. 52.1), more likely to be male...

Abstract Background: The prevalence and perceived effectiveness of marijuana use has not been well studied in inflammatory bowel disease (IBD) despite increasing legal permission for its use in Crohn's disease. Health care providers have little guidance about the IBD symptoms that may improve with marijuana use. The aim of this study was to assess the prevalence, sociodemographic characteristics, and perceived benefits of marijuana use among patients with IBD. Methods: Prospective cohort survey study of marijuana use patterns in patients with IBD at an academic medical center. Results: A total of 292 patients completed the survey (response rate = 94%); 12.3% of patients were active marijuana users, 39.0%...

Although marijuana is now consumed extensively, little is known of its biologic effects on the lung. To study this problem, the intrapulmonary inactivation of an aerosolized challenge of Staphylococcus aureus was quantified in rats exposed to graded amounts of fresh marijuana smoke. Controls inactivated 85.1 percent +/- 0.3 percent of the bacteria six hours after inoculation. Following an in vivo accumulative exposure to smoke from progressively increasing numbers of marijuana cigarettes for periods of ten minutes each hour for five consecutive hours, intrapulmonary bacterial inactivation was impaired in a dose-dependent manner. Evaluation of the effects of parenterally administered delta-9-tetrahydrocannabinol (THC) or of exposure to...

Crude marijuana extract competed with estradiol for binding to the estrogen receptor of rat uterine cytosol. Condensed manjuana smoke also competed with estradiol for its receptor. Pure 9-tetrahydrocannabinol, however, did not interact with the estrogen receptor. Ten i9-tetrahydrocannabinol metabolites also failed to compete with estradiol for its receptor. Of several other common cannabinoids tested, only cannabidiol showed any estrogen receptor binding. This was evident only at very high concentrations of cannabidiol. Apigenin, the aglycone of a flavinoid phytoestrogen found in cannabis, displayed high affinity for the estrogen receptor. To assess the biological significance of these receptor data, estrogen activity was measured in vivo with...

Opioid analgesic overdose mortality continues to rise in the United States, driven by increases in prescribing for chronic pain. Because chronic pain is a major indication for medical cannabis, laws that establish access to medical cannabis may change overdose mortality related to opioid analgesics in states that have enacted them. Medical cannabis laws are associated with significantly lower state-level opioid overdose mortality rates. Further investigation is required to determine how medical cannabis laws may interact with policies aimed at preventing opioid analgesic overdose.

Marijuana has been used for centuries, and interest in its medicinal properties has been increasing in recent years. Investigations into these medicinal properties has led to the development of cannabinoid pharmaceuticals such as dronabinol, nabilone, and nabiximols. Dronabinol is best studied in the treatment of nausea secondary to cancer chemotherapy and anorexia associated with weight loss in patients with acquired immune deficiency syndrome, and is approved by the US Food and Drug Administration for those indications. Nabilone has been best studied for the treatment of nausea secondary to cancer chemotherapy. There are also limited studies of these drugs for other conditions. Nabiximols is only...

Recent advances in understanding of the mode of action of tetrahydrocannabinol and related cannabinoid ingredients of marijuana, plus the accumulating anecdotal reports on potential medical benefits have spurred increasing research into possible medicinal uses of cannabis. Recent clinical trials with smoked and vaporized marijuana, as well as other botanical extracts indicate the likelihood that the cannabinoids can be useful in the management of neuropathic pain, spasticity due to multiple sclerosis, and possibly other indications. As with all medications, benefits and risks need to be weighed in recommending cannabis to patients. We present an algorithm that may be useful to physicians in determining whether cannabis...