Gregory House habitually misuses Vicodin in House M.D.
Vicodin is a prescription combination of hydrocodone and paracetamol, also called acetaminophen. In the series, House takes it to manage chronic pain caused by muscle damage in his right leg, but his use develops into a serious dependence that affects his judgment and relationships.
House’s Vicodin use is a continuing plot element rather than a minor character detail. Colleagues, administrators, and friends repeatedly confront him about withdrawal, concealment, relapse, and the professional consequences of practicing medicine while dependent on the drug.
The show sometimes uses the medication as shorthand for House’s self-destructive behavior. It is not the same as OxyContin, Percocet, or codeine alone. Vicodin is the specific brand-name answer associated with the character.