Gregory House is addicted to Vicodin in House M.D. Vicodin is a prescription painkiller containing hydrocodone and acetaminophen, and House uses it to manage chronic pain in his leg.
House’s limp and dependence on pain medication are central parts of his characterization. The series gradually reveals that an earlier vascular injury caused permanent muscle damage and left him with continuing pain. He believes Vicodin allows him to function while also concealing how severely dependent he has become.
The addiction creates medical, professional, and personal consequences. House lies to obtain pills, experiences withdrawal, enters rehabilitation, and repeatedly damages relationships because of his drug use. His addiction is not merely a character detail; it drives major plot arcs throughout the series.
Other opioids appear in the show, which can cause confusion, but Vicodin is the specific medication most strongly associated with House. The brand name is therefore the canonical answer to this question.