How Safe is Marijuana?

A recent link to Malcolm Gladwell’s article in the New Yorker: Is Marijuana as Safe as We Think? One of my sons informed me of this article.

Excerpt from Malcolm Gladwell’s analysis:

A few years ago, the National Academy of Medicine convened a panel of sixteen leading medical experts to analyze the scientific literature on cannabis. The report they prepared, which came out in January of 2017, runs to four hundred and sixty-eight pages. It contains no bombshells or surprises, which perhaps explains why it went largely unnoticed. It simply stated, over and over again, that a drug North Americans have become enthusiastic about remains a mystery.

For example, smoking pot is widely supposed to diminish the nausea associated with chemotherapy. But, the panel pointed out, “there are no good-quality randomized trials investigating this option.” We have evidence for marijuana as a treatment for pain, but “very little is known about the efficacy, dose, routes of administration, or side effects of commonly used and commercially available cannabis products in the United States.” The caveats continue. Is it good for epilepsy? “Insufficient evidence.” Tourette’s syndrome? Limited evidence. A.L.S., Huntington’s, and Parkinson’s? Insufficient evidence. Irritable-bowel syndrome? Insufficient evidence. Dementia and glaucoma? Probably not. Anxiety? Maybe. Depression? Probably not.

Then come Chapters 5 through 13, the heart of the report, which concern marijuana’s potential risks. The haze of uncertainty continues. Does the use of cannabis increase the likelihood of fatal car accidents? Yes. By how much? Unclear. Does it affect motivation and cognition? Hard to say, but probably. Does it affect employment prospects? Probably. Will it impair academic achievement? Limited evidence. This goes on for pages…

Several points discussed in article:

  • Marijuana may increase the risk of psychiatric illnesses. “Many people with serious psychiatric illness smoke lots of pot. The marijuana lobby typically responds to this fact by saying that pot-smoking is a response to mental illness, not the cause of it—that people with psychiatric issues use marijuana to self-medicate. That is only partly true. In some cases, heavy cannabis use does seem to cause mental illness”…
  • Marijuana may increase aggression,  In the state of Washington was the first U.S. jurisdiction to legalize recreational marijuana. “Between 2013 and 2017, the state’s murder and aggravated-assault rates rose forty per cent—twice the national homicide increase and four times the national aggravated-assault increase”
  • Does cannabis serve as a gateway drug?  Like e-cigarettes, cannabis is being formulated into products attractive to youth: gummy bears, bites, and brownies.

My take (borrowed in part from author): “Permitting pot is one thing; promoting its use is another.” We really don’t know that much about marijuana.

CDC Link: Marijuana and Public Health

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Marijuana Use in Adolescents/Young Adults with Inflammatory Bowel Disease

A recent study (EJ Hoffenberg et al. J Pediatr 2018; 199: 99-105) examined the use of marijuana in 13-23 year age group with inflammatory bowel disease (IBD) at the Children’s Hospital for Colorado.

This relatively small study (n=99 — 62 with Crohn’s, 27 with ulcerative colitis, 10 with indeterminate colitis) found the following:

  • Marijuana use was endorsed by 32 (32%) and that 9 used daily or almost-daily.
  • Users were 10.7 times more likely to perceive low risk of harm (P<.001)
  • 17 of 30 stated a medical reason for use (16 with physical pain)
  • The most common route of use was smoking (83%)


  • 80% of participants had inactive or mild disease
  • There was no control (non-IBD) group to compare frequency of marijuana use
  • Study performed in state with legalized recreational marijuana

My take: We know very little about how marijuana impacts IBD course and whether it is safe.  This study indicates frequent use of marijuana in the 13-23 year age group.  Thus, it is an issue that needs to be examined further.

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Legalized Cannabis Associated with Increased Vomiting and Dependency But What About Alcohol?

In politics, one hears a lot of “What about?”  If a problem is identified, many times a politician will try to divert the focus and/or justify a contentious issue to a related issue with a “what about” question. In medicine, when we see problems with marijuana, one could ask, ‘What about alcohol?’

A recent retrospective study (M Al-Shammari et al. Clin Gastroenterol Hepatol 2017; 15: 1876-81) found an increase in cannabis dependency unspecified (CDU) (ICD code) coinciding with the legalization of marijuana. Thanks to Seth Marcus for pointing out this study.

Key finding:

  • “We observed an increasing trend of CDU or an aggregate of CDU and persistent vomiting…the legalization of marijuana significantly increased the incidence rate during the legalization period (by 17.9%)…compared to the prelegalization period.

Related article: Aaron Carroll Alcohol or Marijuana? A Pediatrician Faces the Question

An excerpt:

The immediate answer, of course, is “neither.” …

The easy answer is to demonize marijuana. It’s illegal, after all. Moreover, its potential downsides are well known. Scans show that marijuana use is associated with potential changes in the brain. It’s associated with increases in the risk of psychosis. It may be associated with changes in lung function or long-term cancer risk, even though a growing body of evidence says that seems unlikely. It can harm memory, it’s associated with lower academic achievement, and its use is linked to less success later in life.

But these are all associations, not known causal pathways…

When I’m debating my answer, I think about health as well…Binge drinking accounted for about half of the more than 80,000 alcohol-related deaths in the United States in 2010, according to a 2012 report by the Centers for Disease Control and Prevention. The economic costs associated with excessive alcohol consumption in the United States were estimated to be about $225 billion. Binge drinking, defined as four or more drinks for women and five or more drinks for men on a single occasion, isn’t rare either. More than 17 percent of all people in the United States are binge drinkers, and more than 28 percent of people age 18 to 24…

Marijuana, on the other hand, kills almost no one…

I think about which is more dangerous when driving. A 2013 case-control study found that marijuana use increased the odds of being in a fatal crash by 83 percent. But adding alcohol to drug use increased the odds of a fatal crash by more than 2,200 percent. A more recent study found that, after controlling for various factors, a detectable amount of THC, the active ingredient in pot, in the blood did not increase the risk of accidents at all. Having a blood alcohol level of at least 0.05 percent, though, increased the odds of being in a crash by 575 percent…

 In 1995 alone, college students reported more than 460,000 alcohol-related incidents of violence in the United States… On the other hand, a 2014 study looking at marijuana use and intimate partner violence in the first nine years of marriage found that those who used marijuana had lower rates of such violence…

[Thus]  if I’m forced to make a choice, the answer is “marijuana.”

My take: While the cited study shows a correlation between cannaboid legalization with both CDU and increased vomiting, the commentary by Dr. Carroll helps provide context to the risks of marijuana use.  From a safety standpoint, the risks posed by alcohol appear much greater.

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Should Medical Marijuana Get a Free Pass?

In many states, including Georgia, medical marijuana has bypassed the rigorous Food and Drug Administration (FDA) approval process via state laws permitting its usage.  A recent editorial (J Koliani-Pace, CA Siegel. Am J Gastroenterol 2016; 111: 161-62 -thx to Ben Gold for this reference) highlights the dilemma facing physicians with medical marijuana with regard to providing advice/approval for this treatment.

Key points:

  • 12% of people aged 12 years or older report using cannabis in the past year.
  • For gastrointestinal illnesses, there is scant evidence effectiveness.  There is some data indicating that it makes you feel better, but no data proving that there is objective improvement in conditions like Crohn’s disease.
  • Adverse effects require more research.  “Approximately 9% of people who experiment with marijuana will become addicted.”  Other concerns: increased car accidents, altered memory/judgment, hyperemesis syndrome, and respiratory effects.  With increasing availability and increasing THC concentrations, there have been in an increase in emergency department visits related to usage.
  • Lack of quality control: various concentrations of THC and cannabinoids, different administration routes, contaminants.

My take: At least with GI illnesses, more studies are needed to determine whether medical marijuana should be recommended.

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Misdirection: False-postive Urine Cannaboid Screen due to Pantoprazole

First of all, this post is not a joke for April 1st. But if you have a good story to tell, please feel free to comment -I’ll share a story at the bottom of this post.

A case report (Felton D et al. Pediatrics 2015; 135: 2014-16) makes a few useful points regarding testing for cannaboids in a patient admitted for cyclic vomiting syndrome.

  1. Intravenous pantoprazole could lead to a false-positive urine cannaboid screen.
  2. Cannabis hyperemesis syndrome should be included in the differential diagnosis for cyclic vomiting. (see previous blog: Think Like a Doctor -Another Reason for Cyclic Vomiting …)
  3. Don’t order every test on the differential diagnosis (my point -not the authors).

With regard to the final point, this particular case report describes a highly-impaired 13 year old with previous diagnoses of intrauterine stroke, global developmental delays, and seizures; she was nonverbal and nonambulatory.  Therefore, despite a positive urine screen, it is not surprising that the confirmatory testing for cannabis via gas chromatography-mass spectrometry was negative.

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On a side note, several years ago we had a little fun in the spirit of April 1st.  One of our neighbors had been complaining for years that they had not received ‘yard of the month’ but had lived in the neighborhood for more than 16 years. So, one year when they were out of town, we managed to borrow the ‘yard of the month’ sign, placed it in their yard, and snapped a picture.  With the collusion of a different neighbor who sends out the monthly announcement, our neighbors were informed of the recognition of their yard. It was definitely a good laugh.  At the same time, I’m a little paranoid about potential payback.



Think Like a Doctor –Another Reason for Cyclic Vomiting

When cyclic vomiting pattern starts in young adults, the differential diagnosis is different than in toddlers.  A case in point is a recent think like a doctor column from NY Times.

The initial presentation described a 25-year-old man who gets sweaty and nauseated and starts vomiting uncontrollably every few weeks.

1st the link with the case challenge: challenged Well readers to figure out

A big clue in this case was the fact that hot showers ameliorated his symptoms.

Now the answer, full link: 

“The correct diagnosis is…




Cannabinoid hyperemesis caused by smoking synthetic marijuana.”

Related blog postDiet or drugs for cyclic vomiting syndrome | gutsandgrowth