Q:  Hypoglycemia & Lithium

I have developed severe reactive hypoglycemia since beginning 300 mg per day of Lithobid. I am happy with the results from the Lithium so I am afraid to change medication but the hypoglycemia is quite severe. Do you have any information on hypoglycemia occuring with Lithium use?


Dear Ms. B' -- 
Hmm, haven't heard that one. Let's try a search: lithium hypoglycemia on PUB MED.  Results: well isn't that interesting, learn something new every day -- yes, you're right, this has been seen before. There's a case report in 1987. That's it, nothing like that since, that I spotted anyway. 

However, there's also a study which looked at this more directly, from 1986^Shah, in which they looked at glucose levels during a "glucose tolerance test" (GTT), a standard lab test for diabetes. They noted that people on lithium had more of a drop in their blood glucose at the end of the test (the "nadir") than those not taking lithium and concluded that indeed "These findings suggest that chronic lithium treatment is associated with a symptomatic and biochemical hypoglycemia during GTT".

Now mind you, this is during a glucose tolerance test. That consists of a big slug of glucose, after which the lab checks blood sugars at several intervals, watching them go up first, and then -- in reaction to the body's insulin production and response thereto -- go down. In this study they saw it go down to 48 where those not on lithium only went down to 62. And those folks at 48 felt funny too, that's the "symptomatic" part of the quote above. 

The point of looking at the GTT in detail is that, at least in this study, the hypoglycemia was a result of the glucose. So there might be at least a part of a solution here, for you, if you and your doctor chose to continue lithium: it might be that your hypoglycemia too is coming from a reaction to your own normal insulin production, that is coming in reaction to glucose you've eaten; and that therefore if you are careful not to get too big a slug of glucose all at once, you might get less of a reaction.  A lot of maybe's in there but it's worth thinking about anyway. Good luck with that -- 

Dr. Phelps