Cocaine

Cocaine, also called blow, (TW: Reset) was a drug, made illegal in the United Kingdom in 1914. (NA: Warlock) Baz Bailey decided to start selling it in the Coal Hill School area. To prevent this, Samantha Jones reported him to the police, but they found no evidence of the substance. To prevent Sam from repeating this, Baz planned to force the drug upon her so that she became addicted. However, the Eighth Doctor prevented this and took the drugs. The police arrived upon the scene and arrested the Doctor for possession of an illegal substance. (EDA: The Eight Doctors)

Barry Leonard started taking cocaine when The Pharm cured his diabetes. (TW: Reset)