My middle daughter had chronic problems when she first started school. Around late morning she would become easily upset, angry, and uncooperative. The school wanted to give her Ritalin, but I pulled her out and homeschooled her instead.
We finally figured out she had a chronic hypoglycemic condition (diabetes runs in my wife's side of the family). If she's allowed a high-carb breakfast, her blood sugar spike, and then crash, and when it crashed she would sometimes go nuts. She would start crying hysterically, get very angry, be repeating the same phrase over and over like a lunatic. The only way to deal with it was to get a little sugar into her somehow (fruit juice or soda), then follow it up with a high-protein meal to level out her blood sugar.
EMTs carry little packets of some jelly-like high-glucose stuff they can put into the mouth of someone having a hypoglycemic attack. If blood sugar is allowed to drop too low and the person goes unconscious, brain damage can ensue as the brain cells are starved of glucose and start to die.
Current EMT training includes procedures for identifying symptoms. Since cops are generally first on the scene when someone is in (or causing) trouble, it seems like a good idea for police to have some basic training in this area, so they don't wind up killing too many diabetics
Every time we have training I ask for something beyond basic first aid. I've had CPR training so many times I've named one of my kids Resesca Annie.
We are not allowed to administer anything to anyone having a medical emergency, other than basic first aid.
What you say does sound like a real good idea. But... it would be easier for Gollum to live without the One Ring.