It is not best to switch to H.
Perhaps ask your PM doc if there could be a higher dose? If you're afraid to ask that, see if he'd give you some gabapentin or lyrica alongside the pain meds. These gabaergic drugs (if taken a few hours prior to your first opiate med dose of the Day ) will potentiate your pain meds. This is my experience anyway and btw -- do NOT speak that term "potentiate" in front of your doctor. Perhaps just let doctor know you feel like the meds are wearing off too soon n see what he says. If HE hesitates to raise dose on painkillers or switch to a stronger / longer lasting one then you could mention you have a "friend" who takes lyrica or gabapentin with theirs and have had success. Ask innocently if that's something you could try adding?
***** pls be aware the medications I have mentioned, if used long term or in large doses, have addiction n withdrawal potential of their own. But my God I would rather see you on this combination, than turning to Heroin.
Pls consider talking w your doctor.