I'm currently taking Diluadid, but it is thru a pain pump. I get all the benefits of the drugs that are in the pump, and none of the side effects. this is because the meds circulate in the spinal fluid and they don't cross the spine brain barrier to cause all the brain fog feeling. It also doesn't go thru the liver, kidneys, etc, again because it never had to leave the spinal fluid. I love it.

Hugs
Mary