New marijuana study on long term lung function

SW VandeCarr

The following published case series of bullous lung disease (a severe form of emphysema) in chronic users of marijuana provides some reason to be cautious in interpreting the results of the JAMA study (MJ Pletcher et al). As Ygggdrasil says, this study focused on a limited number of parameters. To be sure, this case series consisting of just ten patients is small and is not a controlled study. It is insufficient by itself to draw conclusions. However, it suggests a need for caution and further investigation.

http://www.ncbi.nlm.nih.gov/pubmed/18197922

Here's another case series of marijuana users with "small exposure" to tobacco.

http://www.ncbi.nlm.nih.gov/pmc/arti...v055p00340.pdf

FreeFolk

I don't know if anyone is thinking the same thing as me, but I gave a quick look to the pdf file and this can't be compared at all with the previous study that was posted by Mr.Bernhardt.

Out of the four cases brought to attention, 3 are not casual smokers but heavy Marijuana smokers. Several pipe per day and 2-3 joints per day is huge!

I'd like to know if anyone is else is thinking that this research proves pretty much nothing since there are so many factors to take into account and that the research was done with people who mix tabacco and marijuana and who intake massive amounts of marijuana per year... and not to mention this was taken from FOUR cases only...

Any thoughts?

SW VandeCarr

Reputable journals do publish well documented case reports and they do so for a reason. In addition, government agencies such as the US FDA rely heavily on case reports to make regulatory decisions regarding drug safety. It's effectively impossible to do large, expensive studies to verify every safety issue that might arise with drug and environmental exposures. Safety issues are treated differently than efficacy issues. If potential safety problems were not reported, than the public might be justified in asking why such information was not made available. In the US, such omissions have led to successful lawsuits.

I think I made it quite clear that case reports have limited value and conclusions cannot be drawn in a rigorous way. On the other hand, would you favor suppressing such information until some "definitive" study can be done? In that case, many such issues might never come to public attention.

Finally, as Ygggdrasil, said, this study only addressed lung function tests. If you read the reports, you would have seen that some patients with bullous lung disease had normal lung function tests. That doesn't mean they didn't have serious lung disease. The accumulation of such reports is usually the basis for funding large controlled studies. Even this falls short of the standard required for demonstrating efficacy where randomized controlled clinical trials are necessary. Obviously there are ethical issues for doing such studies where there may be a safety problem with one of the interventions.

EDIT: It's also quite easy to document other risk factors in individual cases. In fact, how could a sound treatment plan be developed for an illness if the treating physician couldn't rely on such important historical information and have a reasonable theory of causation for clinical findings? If a patient presented with bullous lung disease, and had a history of marijuana use (with or without tobacco use) would you advise the patient to continue the marijuana use because of the lack of a "definitive" study regarding marijuana and bullous lung disease?

Monique

Yes, just look at the statistics of cannabis users.

First-year statistics: 43% use less than once a week, 7% has daily use.
Past-year statistics: 32% use less than once a week, 10% has daily use.

http://www.ncbi.nlm.nih.gov/pmc/arti.../011536.A1.jpg
From: Am J Public Health. 2004 May; 94(5): 836–842.

SW VandeCarr

I can't speak to the survey you're citing, but in general surveys of this type tend to underestimate actual usage, at least in countries where marijuana is illegal.

http://alcoholism.about.com/od/news/a/blndri060306.htm
http://heinonline.org/HOL/LandingPag...v=46&id=&page=

The real issue is that the risks of marijuana use are still poorly understood and there is some evidence that marijuana use is not as benign as some believe. The utility of well documented case reports should not be underestimated. Many of the good ones document have dechallenge and rechallenge data. When it can be safely done, a positive dechallenge followed by a positive rechallenge is fairly strong evidence of a causal relationship. This would be related to acute inflammation in bullous lung disease.

In the case of bullous lung disease, there is a known relationship with tobacco use. Cocaine has also been associated with this disease.Other known causes are relatively rare and in any case can be excluded by history or tests. A well documented case report of this condition in someone who uses marijuana with little or no tobacco is an important finding. It's quite likely that very low doses are safe, but the effects of long term use even at low doses is not at all well understood.

http://www.ctsnet.org/sections/clini...article-1.html

Monique

The statistics that I cited is for condoned cannabis use in Amsterdam, statistics for San Francisco are very similar (see graph). The percentages match my personal observations, although I agree that self-reported observations are not as reliable as actual measurements.

PhysiPhile

I smoke pot on a daily basis but wouldn't touch a tobacco product. There's one data point FWIW.

PhysiPhile

I thought I would attach a PDF that is probably the most comprehensive look at the pharmcokinetic/dynamic properties of cannabinoids. This even cites research associated with distribution (pharmacokinetics) of cannabinoids in a fetus and breast milk.

Attached Files

some stuff about stuff.pdf (455.8 KB, 18 views)

gravenewworld

Use a vaporizer to inhale MJ and many of these studies become almost irrelevant. It ridiculous that marijuana continues to be illegal, especially for medical use.

PhysiPhile

Aged cigarette smoke actually has been shown to be much more carcinogenic. So there is reason to believe vaporizers would be worse for you since the smoke has aged more.

Also, what is the difference in the smoke from a vaporizer and a gravity bong? Vaporizer is kind of superfluous in my opinion.

Pythagorean

no, vaporizer's don't burn the cellulose, just the oils. Bong burns the cellulose and lets plenty of smoke through. You can't really even see the smoke with a good vaporizer.

I'm curious, what do vaporizers have to do with aged smoke?

PhysiPhile

Haven't looked into much about vaporizers but I assumed they reach a temperature just enough to vaporize the THC but not other carcinogenic plant matter. Do you know the purity of vaporized smoke and smoke from a GB?

This doesn't look clear to me:


So I'm saying that the more you let the smoke sit, the more carcinogenic the smoke is (if you can extrapolate from cigarette studies).

Pythagorean

Since you're targeting the smoke point of THC and not burning the cellulose (there's still a bud leftover after you vaporize it) you have to be careful about what you extrapolate from a cigarette study (which doesn't have THC and which does burn cellulose). I don't know any numbers.

Posting a single picture is pointless. There's lots of problems with that kind of comparison; in that bag there's a bigger volume than in a bong and besides not knowing the camera's specificity, it's a darkly lit room. Additionally, the temp is set up pretty high on that vaporizer (6.5/9). We also don't know what kind of marijuana is in the vaporizer, how it was grown, or if that was even marijuana smoked in it. These all make a lot of difference. Additionally, the temperature could be set high because of wet bud. How much is steam?

The theory of the bong is that the water filters it, but the water doesn't actually filter everything. As bubbles pass through the water, only the contents on the edge of the bubbles get held behind, so it's actually quite a crude filter. If you have a way to percolate the bubbles and diffuse them more, then you are getting a better filter.

So lots of variables in the end, really. But I am willing to bet (not that I would personally know :) that if you compared vaporizer and bong smoke in a proper comparison, the bong smoke would have many more impurities per psychoactive substance.

PhysiPhile

I've never even seen a vaporizer before so I'm not expert on the smoke it contains. A internet picture is the best I can do. I would assume the density of smoke correlates with it's carcinogenicity so I need to see the smoke you're talking about.

Right, surface area is much higher with smaller bubbles, and surface area matters most in this case. I think the only point of a gravity bong is to allow the smoke to cool.

How about rectal administration haha (from pdf above):
I don't know why they would use monkeys - I have several friends who would have volunteered after wasting their last 5 bucks on a cannoli and scratch and sniff stickers.

Pythagorean

haha, wow, who'd have thought... now they just need to come out with cannabis toilet paper.