Yeah, it's a good aid for opioid withdrawal. Interestingly this effect appears to be there even with tolerance, I was prescribed 600mg/d morphine and 600mg/d pregabalin for months, the pregab had no more noticeable effects for a long time but I could still do a rapid taper of morphine down to around 90mg/d without suffering which I attribute to the pregabalin. It's a weird substance. But I got it prescribed for social and general anxiety and it definitely stopped working for that. The effects I got from my first 900mg's, many years ago, are still under my top 3 drug experiences but could never been reproduced. I just kept taking it because I was afraid of the withdrawal which should prove wrong in the end.
Major side effect I encountered was a fucked up short term memory, I remember watching the newest Spider Man in cinema and couldn't follow the plot because I kept forgetting what just happened. This was on 1.2g if I'm right but even 600mg/d felt kind of stupidity inducing.
Did you get stimulant and/or detached effects from these high dosages?
But I think you're lucky to having survived this high dose habit. My DOC I was primarily abusing were dissociatives (deschloroketamine) and at some point of ridiculously high dosing I began to encounter alarming physical effects, like water retention in the legs, pain in the testicles, eventually stuttering and slightly yellow-ish skin color, I think it could have killed me but I didn't think a second about quitting.