Opioids How long before I can safely redose?

Hello all. I've looked for the answer elsewhere and can't really find much, maybe I'm doing it wrong, I don't know.

How long do I have to wait before I can dose again for an opiate, and not have it build upon my previous dose? I took an 80mg oxy and 8mg of dilaudid over nine hours ago, and I want to take another 40mg of oxy now.

But I'm confused as to whether the oxy I would take now, would build upon what I took just after noon? Or would it be like starting fresh, just 40mg of oxy and that's it?

I wouldn't want to inadvertently cause and overdose because of stuff I took earlier in the day. So how long generally is a safe amount of time to wait?

Thank you

Regarding solely the risk of acute opioid overdose, once your high is over you aren't going to be able to build on your previous high. So as a generalization if you've come down and feel back to normal it is 'safe' to use again. You can also look up how long lasting certain opiates are and use that to judge if it is okay to use again.

edit:
This is better suited in BDD but as it's answered I'll just close it for now.
PM me if you have any questions.

It's really a specific answer for a specific person. It depends on your tolerance and metabolism. No one can really give an accurate answer. For me, I could take another 40 mg exactly 3 seconds after taking what you did. For safety sake, I'd say 24 hours to be safe, and 12 hours if you want to risk it.... but be careful. Try taking a piece of the 40mg pill if you have to and if all is well in an hour take another piece. Again, for harm reduction sake you should wait as long as possible.