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. However, people who have continuing pain should not let the fear of dependence keep them from using opioids to relieve their pain. Mental dependence (addiction) is less likely to occur when opioids are used for this purpose.