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Medical marijuana: 5 things you should know

In January 2014, Colorado became the first U.S. state to pass a law allowing the sale of recreational marijuana use. The passing of this law brought about the possibility for potential public health implications.

In a recent perspective published in The New England Journal of Medicine, Tista S. Ghosh, MD, of the Colorado Department of Public Health and Environment, and colleagues addressed some of the relevant concerns and the ways in which Colorado has attempted to avert negative population health effects following the expansion of the legal availability of marijuana.

“Colorado has been examining ways of applying lessons from 14 years of medical-marijuana legalization and from alcohol- and tobacco-related policies,” they wrote.

In addition to the enactment of laws limiting marijuana-use to those aged over 21 years and the extension of indoor smoking restrictions to include marijuana, the state developed surveillance systems aimed at monitoring the number of emergency department visits and hospitalizations associated with marijuana use. Moreover, public awareness campaigns have been developed that address safe storage of marijuana, including edible products.

“The availability of diverse edibles puts young children at risk for unintentional poisoning,” Ghosh and colleagues wrote. “States where medical marijuana is legal have been shown to have higher rates of calls to poison-control centers for unintentional marijuana exposure in children under 9 years of age, and more patients sought care at a Denver-area children’s hospital because of unintentional marijuana use after medical marijuana became commercially available.” 

Healio.com/Internal Medicine presents 5 “fast facts” about the current issues surrounding medical marijuana use.   

1. Rates of accidental ingestion increased among children.

An increase in unintentional consumption of marijuana by young children has been observed following the decriminalization of medical marijuana in Colorado, according to study results published in JAMA Pediatrics. Among 1,378 children aged younger than 12 years, researchers found that the number of ingestion visits increased after Sept. 30, 2009, from 0 of 790 (0%; 95% CI, 0-0.6) to 14 of 588 (2.4%; 95% CI, 1.4-4). Eight of the 14 cases involved medical marijuana, of which seven were from food products. Read more

2. Chronic marijuana use may be linked to brain abnormalities, poor memory.

Heavy marijuana use may be associated with abnormal alterations in the brain structures of teenagers that particularly affect memory, according to study results. Specifically, younger age when beginning marijuana use was associated with more abnormally shaped brain regions. Of note, abnormalities associated with marijuana use appeared similar to schizophrenia-related brain abnormalities. Of 15 patients included in the study with schizophrenia who used marijuana, 90% reported chronic use of the drug before developing the disorder. Read more

3. Clinicians have increased concern for potential allergens associated with Cannabis sativa.

Researchers analyzed data documenting cases of allergic reactions to marijuana and found that inhaling Cannabis pollen has been linked with symptoms including allergic rhinitis, conjunctivitis and asthma. In addition, exposure to the smoke of Cannabis has been associated with coughing, sneezing, nasal congestion, rhinitis, wheezing and dyspnea. The researchers also found that growers of marijuana could face occupational hazards such as urticaria, periorbital angioedema and generalized pruritus.  Read more

4. Most pro-marijuana tweets are sent and received by those aged younger than 25 years.

A study published in the Journal of Adolescent Health involving 7.6 million tweets associated with marijuana sent during a 1-month period in 2014 indicated that 77% of tweets were pro-marijuana. Of these, the majority of tweets originated from users aged younger than 25 years —  many were teenagers, according to the researchers. Read more

5. Adolescents do not understand the risks of marijuana use.

A recent Monitoring the Future survey measuring drug use and attitudes among eighth-, 10th and 12th-graders found that compared with 44.1% of 12th-graders that viewed marijuana use as harmful last year, 39.5% viewed it as harmful in 2013. Moreover, the rates of daily marijuana use among 12th-graders increased during the past 2 decades from 2.4% in 1993 to 6% in 2003 and 6.5% in 2013. Read more