A 44-year-old businessman with a history of hypertension presents for evaluation with a report of being under stress at work and home, which has led to “unsatisfactory” sleep. Although there is some despondency, screening for depression is negative. His blood pressure is 158/98 mm Hg. Laboratory results include a mean corpuscular volume of 102 fl (normal range, 80 to 100), an alanine aminotransferase level of 60 U per liter (normal range, 7 to 41), an aspartate aminotransferase level of 45 U per liter (normal range, 12 to 38), and a γ-glutamyltransferase level of 110 U per liter (normal range, 9 to 58). His physician asks about alcohol consumption, and the patient admits that perhaps he drinks “more than he should,” since he often wakes up with a hang-over and arrives late to work. After weekend golf outings, he comes home intoxicated, leading to arguments with his wife and embarrassment in front of his children. He has been quietly wondering about the need to cut down or stop drinking and wants some advice. His physician discusses medication or a referral to an alcohol clinic for further evaluation. Naltrexone is proposed as a treatment option.

A 25-year-old man presents to the emergency department with a toothache. During the evaluation, the physician determines that the patient has been taking large doses of over-the-counter acetaminophen along with an acetaminophen–hydrocodone product for the past 5 days. His daily dose of acetaminophen has been 12 g per day (maximum recommended dose, 4 g per day). He has no other medical problems and typically consumes two beers a day. The patient has no symptoms beyond his toothache, is not icteric, and has no hepatomegaly or right-upper-quadrant tenderness. His serum acetaminophen concentration 8 hours after the most recent dose is undetectable. His serum alanine aminotransferase concentration is 75 IU per liter, his serum bilirubin concentration is 1.2 mg per deciliter (20.5 μmol per liter), and his international normalized ratio (INR) is 1.1. The emergency department physician contacts the regional poison-control center, which recommends treatment with acetylcysteine.