Hydrocodone is a strong opioid pain medicine used to manage severe, around-the-clock pain that needs daily, long-term treatment with an opioid, and only when other pain treatments, such as non-opioid medicines, do not control the pain well enough or are not tolerated. Hydrocodone is used to relieve severe pain. Hydrocodone is in a class of medications called opiate (narcotic) analgesics. It works by changing the way the brain and nervous system respond to pain. This monograph only includes information about the use of hydrocodone alone. Hydrocodone belongs to the group of medicines called opioid analgesics (pain medicines). It acts on the central nervous system (CNS) to relieve pain. When hydrocodone is used for a long time, it may become habit-forming, causing mental or physical dependence. Hydrocodone and oxycodone are both opioid pain relievers. Learn how they’re different and how to safely use them. Find patient medical information for Hydrocodone/Acetaminophen (Norco, Vicodin, others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Hydrocodone is used to treat moderate to severe pain. In liquid formulations, it is used to treat coughing. [11]. In one study comparing the potency of hydrocodone to that of oxycodone, it was found that it took 50% more hydrocodone to achieve the same degree of miosis (pupillary contraction). [27]. Learn about the side effects of hydrocodone, from common to rare, for consumers and healthcare professionals.