https://mayomeds.com/pain-relief/hydrocodone/ https://mayomeds.com/pain-relief/hydrocodone-5-325-mg/ Hydrocodone belongs to the category of medications classified as opioid analgesics, commonly referred to as pain relievers. Hydrocodone 5-325 mg is an opioid-based analgesic used for pain relief. It is available for online purchase to manage severe pain. Medical professionals typically prescribe this medication for chronic pain only when other non-narcotic treatments have proven ineffective.