Based on bioavailability and my knowledge of morphine it would probably be about 1.75x. Thus 30mg = 53mg. Only tried it orally and IV, but rectal administration should be equivalent to more than 1.5x but probably (though not necessarily) less than 2x.
Rectal admin is hit and miss for me.
You definitely getting more than thirty percent but I call bullshit on any higher than sixty.
It doesn't last long I've injected morphine and it was a complete overwhelming experience.
76% is certainly closer to 100% than 20% that's all I meant. I haven't memorised the exact numbers (thanks for adding that info) but my main point was some simple HR: a regular dose of oral morphine can easily be a high dose of plugged morphine. And just as I thought, 30-76 is a HUGE variation, so if someone has never done it before starting on the low end is the smartest idea.
If I take morphine orally I can easily do 100-200mg and be fine. I'm pretty sure if I plugged that dose I would face a real chance of OD. The increase in BA is significant enough that the dose needs to be significantly reduced. That's all I'm saying.
I'd say start at 100mg max, maybe even a bit lower, and see how you feel. If it's not enough you can always redose. Since the variation in BA is quite large it's worth sticking to the safe side by taking a lower dose to work out how strong it feels subjectively for you.
The thing is, there are so many factors are coming to play with plugging vs oral that it's very hard to give a definite bioavailability figure. Even if you Google it you get about 7 different numbers for rectal morphine BA.. Personally I've never found plugging to be any more effective than oral and many times it even less effective