Don? Get it -are you asking if demerol(pethidine) is water soluble? Surely it has no APAP
As Calderone said, be careful, Demerol is an opioid, so adding it with hydro or whatever causes synergistic effects - they can enhance each other - however Demerol is also a somewhat atypical opioid; it can have odd side AFAIK, and at high doses is simply toxic-people worry so much about apap without knowing about other things, like CNS toxicity from pethidine and it?s metabolite
This and it being a mild opioid, and the vast range of other options(opioids) that are available have caus d it to fall out of favour generally, though for reasons unknown to the general public, some MD?s still have a tendency to use them