Vicodin is a synthetic opioid with a hydrocodone component. It triggers the same neurotransmitters as heroin and other opiate drugs. Acetaminophen tablets and hydrocodone bitartrate are the generic names for Vicodin. Similar brand-name pain relievers like Lorcet, Norco, Lortab, Hycet, and Xodol contain the same medication combination. Vicodin, like all painkillers, works by blocking the receptors on nerve cells in your brain that cause pain. To put it another way, Vicodin makes you more tolerant of pain by stimulating the nerves that cause it.