Morphine 60s

[effie]

Since I don't use those charts or even attempted to look at them, are you actually saying 15mgs of hydrocodone is equal to 15mgs of morphine?

Well. Anecdotally (from most posters and my own experience of morphine being pretty shite orally, not had hydrocodone) - no. According to the charts, which were researched (although being revamped currently) - yes.

Plugging morphine again technically doesn't have a significantly improved bioavailability, but anecdotally (and IME) it is better than oral.

 

[SPC123]

Plugging morphine does in fact lead to a significantly increased BA, considering it's only 20-40% orally, and can hit 70% rectally. Copy/Paste my post from another thread:

On plugging morphine:

"The Bioavailability of Rectally Administered Morphine", Torsten Jonsson, Christian Broen Christensen, Henrik Jordening, Carsten Frølund
Abstract: Plasma concentrations of morphine were followed for 24 hours in eight patients after intravenous and rectal administration of 10 mg morphine chloride. The plasma levels of morphine were determined by a sensitive and specific radioimmunoassay based upon an extraction procedure which separates morphine from its major polar metabolites. The bioavailability of morphine after rectal administration was found to be 53.3 ± 17.8% (mean ± S.D.). Peak concentrations of 16.3 ± 8.7 ng ml-1 were reached after 59 ± 16 min. The study indicates that first pass elimination of morphine may be partially avoided by rectal administration.

 

[effie]

Interesting most of the figures I've seen have put it fairly equal, in the 30% region. We do need to update our bioavailability thread (it is being looked at) but it's hard when sources give such varying percentages. All we can do is give a range and cite our sources I guess.

I have definitely noticed that people on the forum tend to rate it higher than oral, and my experience definitely fits with that.

 

[SPC123]

Well a large part of the problem is that people differ so much in how they metabolize drugs. The source I cited puts the rectal BA anywhere from 35-70%. Quite a steep curve. I think in updating our bioavailability thread the main focus should be to ensure people understand exactly how variable this can be. Further it may be helpful to express BA values in relation to one another rather than absolutes. Someone who experiences a low oral BA with morphine (for example) is more likely to also fall lower on the scale for rectal administration. Using oral as a baseline (since that's what the majority of people will have experience with when it comes to pharmaceuticals) we could say "An individual can expect rectal morphine BA to be approximately twice as high as oral." Leaving the numbers out ensures people use their own subjective experience in addition to our guidelines on what to expect. When you start talking about drugs like fentanyl slight deviations in BA could literally mean the difference between life and death.