Why does methadone make you feel like passing out?

I was a heroin user for 10 years and when i decided enough was enough, I went on to methadone I started off on 90 mill used that does for about a month,then took it down to 40 mill,I was advised against this but thought I'd manage and wanted myself off it,it didn't affect me and i was fine,I dropped 10 mill every month again this did not affect my sleep pattern etc It's been 14 months since I started using methadone and I'm now on 4 mill not a lot I know some days I don't take it and have not done so now for 6 days,I have been fine apart from my feet nothing to much,it's something I can handle.

You are very unique, kicking (detoxing) methadone is way harder than heroin, heroin detox is like a bad FLU, with the sleepless nights, tossing and turning, hot & cold flashes, mood swings, diarrhea, no energy, every nerve stands on end, libido is shot. But the up side is it ONLY lasts 3-5 days, then GO TO MEETINGS, I cannot stress the importance of meetings which should start before the Detox. No macho bull, no, I can kick on my own, U can't, without help from people that been there. I been there, Heroin user for 15 years and I'm only 35. Been on Methadone for 3 years, switched over to suboxene, gradually detoxing and going to meetings, plan to be drug free before I turn 37.

A slow detox on Methadone can take 6 months to a couple of years, 21-day detox DOES NOT WORK. Big Pharma got us hook, line and sinker, but we can win.