There is not a huge amount of information about concomitant use of marijuana in people with diabetes. Harold Starkman wrote a chapter in a textbook I edited many years ago, and there are periodic articles that have been published since that time that say pretty much the same thing we learned from our own experiences and from the literature review we did. What we know clinically is as follows:

1. Biggest risk of marijuana use is that it is illegal and therefore subject to all the problems of getting busted.
2. Driving a car while under the influence of marijuana is dangerous since the brain is "under the influence." There is increasing information about accidents caused by or associated with marijuana use. Studies are difficult since concomitant alcohol and other drug use is also likely under such circumstances. Since many people, especially teens and young adults, do not believe that marijuana use is harmful, they are likely to also not realize the dangers of driving, making decisions, changed reflexes, etc.
3. Similarly, for all folks (including teens with diabetes) when smoking marijuana, likely that one will not make excellent decisions about food, insulin, activity, sexuality, etc. Therefore, like all other drugs that influence the brain, while under the influence of marijuana, risks exist. This would suggest, from a common sense perspective, that there would be higher chance of dosage errors, mistakes about how to respond to blood glucose results and perhaps also timing errors. All likely would be worsened if hypoglycemia were to occur. Marijuana per se does not cause or increase hypoglycemia nor does it block the body's response to hypoglycemia.
4. Marijuana, in clinical research settings, raises the blood glucose slightly but not enough to think this would be important clinically at any moment in time or even if this slight higher sugar level could be detected with usual meters. If one were stoned frequently, however, this may be unhealthy.
5. Long term marijuana use is also very toxic to the lungs and since smoked without any type of filter likely would contribute to a variety of allergic and/or carcinogenic potential problems. This is also controversial medically but makes some sense since whatever is in marijuana is certainly not processed or refined in any fashion. This is also, of course, the same whether or not in a person with or without diabetes.

This reply was written by Stuart Brink, M.D.