With opiates you can take a much lower amount of time release than if you try to regulate your pain (more frequently) with immediate release. Finding the most ideal combo and when you take them is a matter of trial and error.

Also, don't ignore the role food (especially carbs) and exercise can make on your grogginess. Things you might have been able to get away with prior, you may no longer be able to. Cue a line of dancing bananas!