I definitely don't have the part pre-medications, and I have the caffeine jitters only sometimes - less than once a week. I'm taking concerta for reference.

I'm very curious about the pre-medication jitters. It feels to me more like anxiety/anticipation than a symptom of medication. What happens if you delay taking medications after you start thinking about it? What do you associate with taking medications? Do you start working or "being in focused mode" right away? I tend to get more jitters if I "need" my meds to be effective soon vs having a bit more time for them to activate fully.

Strange! Do you get the heart racing feeling when the meds are actually active, or only in that time before the meds kick in? The closest I've gotten to this is that I'll often wake up to take my first dose of medicine about an hour before I really need to get up. If I'm anxious about something happening that day (work, appointment, etc) then I'll stress myself out trying to get myself to fall asleep before my meds kick in, knowing I won't get a chance to fall back asleep again, and that anxiety sort of causes a faster heart rate. But not really related to the medicine, as it's the same anxious reaction I would get back in college when I'd stay up too late studying for a test and then desperately try to fall asleep only to stay awake the whole night before the test 😅 lol

Any chance it's something like that, anxiety/stress related?