I get these headrushes as well. I’ve been on the max dose of this drug for years now. I first noticed it was the drug cause the headrushes would always for sure happen 8-12 hours after missing a dose. But I also get them if anything stressful is on my mind or anything to do with confrontation. I’m tapering off the drug now cause while it’s not constant, it’s extremely unsettling. Gotta do what’s good for you, doctors weigh pros and cons on paper, only you know what you can handle and what is too much.