Learn about the side effects of hydrocodone, from common to rare, for consumers and healthcare professionals. Hydrocodone is a potent opioid used to manage severe and persistent pain that requires an extended treatment period with a daily opioid pain medicine, when other non-opioid pain medicines do not treat your pain well enough, or you cannot tolerate them. 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]. Hydrocodone belongs to the group of medicines called opioid analgesics (pain medicines). It acts on the central nervous system (CNS) to relieve pain, and stops or prevents cough. When hydrocodone is used for a long time, it may become habit-forming, causing mental or physical dependence. Hydrocodone/acetaminophen is a narcotic drug used as a pain reliever to treat moderate to moderately severe pain and cough suppressant. Side effects include lightheadedness, dizziness, sedation, nausea, and vomiting. 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 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 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 a prescription narcotic indicated for the management of severe pain. Learn about side effects, drug interactions, dosages, warnings, and more.