Norco 5-325 mg is a prescription pain-relief medication used to treat moderate to moderately severe pain. It contains two active ingredients: hydrocodone bitartrate (5 mg) and acetaminophen (325 mg). Hydrocodone is an opioid analgesic that works by changing how the brain and nervous system respond to pain, while acetaminophen is a non-opioid pain reliever and fever reducer that enhances overall pain control.