A 29-year-old woman is admitted with nausea, jaundice and right upper-quadrant discomfort. Her alanine aminotransferase is 9200 U/L (5–40), aspartate aminotransferase 7600 U/L (5–35), bilirubin 62 micromol/L (3–20) and INR 2.0 (0.8–1.2); lactate dehydrogenase is 18 000 U/L (100–250). Viral serology is negative and an acetaminophen concentration is undetectable 36 hours after presentation. Her partner reports that she was hypotensive at 75/40 mmHg for approximately 30 minutes during a prolonged episode of vomiting the previous day. Which one of the following is the most likely diagnosis?