Norco 5-325 mg is a prescription drug used to treat moderate to fairly severe pain. Acetaminophen (325 mg) and hydrocodone bitartrate (5 mg) are its two active components. Acetaminophen is a non-opioid pain reliever and fever reducer that improves overall pain control. In contrast, hydrocodone is an opioid analgesic that acts by altering how the brain and nervous system react to pain.