Sounds like it's one of these:
Imprint Code: 54 543
Drug/Strength/Manufacturer:
Oxycodone HCl 5mg /
Acetaminophen 325mg -
Percocet - Roxane
Description: Tablet - White - Round
Imprint Code: 54 543/scored
Drug/Strength/Manufacturer: Oxycodone HCl 5mg / Acetaminophen 325mg -
Roxicet - Boehringer lngelheim
Description: Tablet - White - Round
Oxycodone is used to relieve moderate to moderate-to-severe pain. It also is used to relieve postpartum, postoperative, and dental pain.