The addict died of a drug overdose.

Literal

That addict [topic-は] narcotics [possessive-の] excessive-intake [by-で] died.

中毒者 'addict.' 麻薬 'narcotics.' 過剰摂取 'overdose/excessive intake' — 過剰 'excessive' + 摂取 'intake.' A blunt news-report style sentence.