Hydrocodone is a prescription pain medication used to treat moderate to severe pain. It is an opioid, which means it works by binding to opioid receptors in the brain and spinal cord to block pain signals.Hydrocodone is available in both brand-name and generic forms. The brand-name forms of hydrocodone include Vicodin, Norco, and Lortab. The generic form of hydrocodone is simply called hydrocodone bitartrate.