I Have A Current Prescription For Hydroxyzine That's Labeled H

I have a current prescription for hydroxyzine that's labeled H on one side and 105 on the other side. I just received a refill from the same manufacturer for the same 10 mg drug but the tablet is larger and is marked H 500. I'm concerned that the pharmacy may have given me a different dose or a different drug. How should I handle this situation? I can't identify the H 500 product in any online pill identifier.