Which of the following clinical tests may be influenced when a toxic dose of acetaminophen has been ingested?

Which of the following clinical tests may be influenced when a toxic dose of acetaminophen has been ingested?

• A. Alanine aminotransferase
• B. Ammonia
• C. Blood pH
• D. Calcium

Answer: (A)

Acetaminophen overdose primarily damages the liver. When liver cells are injured, enzymes that normally stay inside the cells spill into the bloodstream. Alanine aminotransferase is a liver-specific enzyme, so its level rises clearly in hepatocellular injury from acetaminophen toxicity. Ammonia can increase if liver failure becomes severe, but that isn’t as direct or early a marker of this specific overdose. Blood pH and calcium aren’t reliably affected by the typical liver injury seen with acetaminophen toxicity. So ALT elevation best reflects the hepatocellular damage caused by a toxic dose.

Acetaminophen overdose primarily damages the liver. When liver cells are injured, enzymes that normally stay inside the cells spill into the bloodstream. Alanine aminotransferase is a liver-specific enzyme, so its level rises clearly in hepatocellular injury from acetaminophen toxicity. Ammonia can increase if liver failure becomes severe, but that isn’t as direct or early a marker of this specific overdose. Blood pH and calcium aren’t reliably affected by the typical liver injury seen with acetaminophen toxicity. So ALT elevation best reflects the hepatocellular damage caused by a toxic dose.