Nausea and hiccups. Generally nausea though. With that kind of tolerance you'd have to go pretty far for it to be dangerous (without any other CNS depressants active). It's probably damn hard to OD on oxycodone if you don't all of the sudden double your ideal dosage, and you take it orally and by itself.
Your area postrema (vomiting center outside of the blood brain barrier) is pretty good at showing you when you've pushed it too far orally.
Do not take any other depressants.
Yeah, Oxycodone is really short acting, so you would know within an hour if anything was wrong, are these the pure oxycodone (Roxi) or the type that have acetaminophen in them? Im guessing its the 15mg or 30mg teeny tiny greenish/ bluish pills though. Ive taken alot of those, they are good but dont last long, and we were paying roughly $1 per mg...but this was back when they could be had easily, not so easy to get ahold of today, most have went to H now, all due to the damn new state laws regarding pill mills and doctor shopping..I guess they thought all those pill heads would just stop using altogether if they had problems getting their pills?!! LOL Yeah right!!
Concerning ODing, I partied one night with my GF at the time, she was taking roxi 30s, drinking wine, I was taking a crap load of methadone 10mgs, and drinking whiskey, we ended up fighting and yelling at each other in her driveway at 5am, I drove home, (not sure how I made it), I remember pulling in my driveway, and getting out of the car, I remember it was still dark and probably around 5:30am, but not sure what happened after that, I dont remember the next 3 hours, all I remember is suddenly waking up, or 'coming to' standing there right beside my car...but the sun was now up and it was going on 8:30am....I guess I stood there for 3 hours??? not sure why I didnt fall to the ground or pass out, this was very strange, I remember feeling very weird and wondering how I stood there for 3 hours, and if this was real... I went in and got in bed, but was kinda scared to go to sleep, I eventually did, but that was the closest Ive been to the edge, Im not sure how much methadone I took over the course of that night, but it was at least 1o-10mg tabs, plus the whiskey on top.