Hydrocodone bitartrate extended-release tablets are an opioid agonist indicated for the management of severe and persistent pain that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids. (1) Hydrocodone is used to help relieve severe ongoing pain. Hydrocodone belongs to a class of drugs known as opioid analgesics. It works in the brain to change how your body feels and responds to pain. Do not use the extended-release form of hydrocodone to relieve pain that is mild or that will go away in a few days. Norco (hydrocodone bitartrate and acetaminophen) is an opioid analgesic and antitussive (cough suppressant) combined with a pain reliever (analgesic) used to treat moderate to fairly severe pain. Hydrocodone is an opioid that binds to specific receptors in your body to give you pain relief. Common side effects may include constipation, dizziness, drowsiness, headache, and stomach pain. Long-acting opioid pain medicines, such as hydrocodone bitartrate ER tablets, can put you at risk for overdose and death. Even if you take your dose correctly as prescribed, you are at risk for opioid addiction, abuse, and misuse that can lead to death. Single-dose pharmacokinetics of 2 or 3 tablets of biphasic immediate-release/extended-release hydrocodone bitartrate/acetaminophen (MNK-155) under fed and fasted conditions: two randomized open-label trials. Hydrocodone Bitartrate prescription and dosage information for physicians and health care professionals. Pharmacology, adverse reactions, warnings, and Hydrocodone Bitartrateside effects. 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. There is a greater risk of overdose and death with extended-release opioid formulations, including hydrocodone bitartrate. This drug should be used only when other treatments have failed to provide relief. Hydrocodone bitartrate is a phenanthrene-derivative opiate agonist antitussive and analgesic agent. Hydrocodone bitartrate and hydrocodone polistirex are used in combination with other antitussives or expectorants for the symptomatic relief of nonproductive cough.