I'm having the same problem with Opana ER. It only seems to last about 8 - 9 hrs. I really wish it worked for the full 12. I seem my dr. this tues. and he is going to up my dose again. I'm on 20 2xa day and I think he is going to take me up to 40mg. Boy, it means another week of sleeping all the time till I get used to it. But boy, when it works it is great!
Hugs,
Mary
ps. see my new kitten. yes it does look like she has eye liner on.