In House M.D., House is addicted to Vicodin for pain relief.
Vicodin is a brand name for a prescription combination of hydrocodone and paracetamol, also called acetaminophen. In the series, House takes it to manage severe chronic pain caused by a damaged leg muscle.
His dependence on the drug is a major continuing storyline rather than a minor character detail. It affects his judgment, relationships, employment, and willingness to accept medical help. Several plots examine withdrawal, relapse, concealment, and the consequences of prescription-drug misuse.
The show sometimes treats House’s addiction through medical drama and sometimes through character conflict. Vicodin is therefore associated specifically with House, but it is not a fictional drug: it is a real prescription medication whose formulation and availability have varied by country and period.