Rule #1: Ask Questions, Even if You Think They're Stupid. Rule #2: Use Google

One of my group home residents had all kinds of problems that I and several specialists have grappled with. In the past few weeks, he developed a new one. He had already had episodes of altered consciousness without cardiac or neurologic explanation.

Not long ago, a second neurologic opinion suggested that the patient's risperidone, a modern "atypical" antipsychotic might be the cause. So the psychiatrist switched the patient to quetiapine, another drug in the same class. Personally I find quetiapine a scarier drug in many ways, but my patient seemed to have fewer episodes on the new drug. But two weeks ago there seemed to be new spells, and they included low blood sugars. My patient is not a diabetic, but one of the lead workers at the group home is a former medical assistant of mine with a very good head on his shoulders. He checked the blood sugar and it was lower than expected for the time of day and foods eaten. Blood sugars had never been low in this patient before, even during near collapses.

When I heard about this, I ordered a paired fasting blood sugar and insulin level. They wre normal, making an insulin producing tumor an unlikely explanation.

In today's visit, D. posed the question "do you think the quetiapine could be the cause?"

"I don't know", I said and googled "quetiapine hypoglycemia" and, sure enough, there was a case report of just this apparent side effect.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7387607/#:~:text=By%20interacting%20with%20these%20receptors,cells%20and%20thereby%20cause%20hypoglycemia.&text=Insulin%20is%20secreted%20by%20pancreatic,the%20islets%20of%20Langer%2Dhans.

"How helpful is the quetiapine for the moods, compared to the risperidone?", I asked.

"Better", D. answered. "And the day we did the fasting bloodwork, which is when the sinus surgery took place, he was off the wall and the anesthesiologist had to give him Haldol."

So we agreed to keep the quetiapine, schedule snacks between meals and monitor the blood sugars. But at least we think we know what's going on. Hopefully we can work around all this...