(hydromor Is an pain medication. An is sometimes called a narcotic. is used to treat moderate to severe pain. may also be used for purposes not listed in this medication guide.Important information about can slow or stop your breathing, especially when you start using this medicine or whenever you dose is changed. Never take in larger amounts, or for longer than prescribed. Do not crush, break, or open an extended- Release pill. Swallow it whole to avoid exposure to a potentially fatal dose