I Had Spinal Fusion 4 Weeks Ago, & Was Prescribed

I had spinal fusion 4 weeks ago, & was prescribed hydromorphone & hydrocodone. As I've healed the pain has improved substantially. I manage it primarily with Tylenol now, but if work & therapy have been hard I do resort to 2-g hydromorphone.
I am concerned though about liver damage with hydromorphone. Is it similar to that of acitomenophen / hrydrocodone?