DPH potentiates greatly, especially if you only have a small amount of hydromorphone
to work with. Try grapefruit juice thirty-45 minutes pre-dose too to get the biggest bang for your friends buck.
But be careful with how hard the nod can become with the DPH combo...its truly surprising the kick it can add.
My canary has had a personal experience where he has actually fallen asleep in the shower from a DPH potentiated opioid
nod haha. pretty powerful stuff.