Which of the following are contraindications to acetaminophen use?

• A. Liver disease; known hypersensitivity; taken acetaminophen in last 4 hours
• B. Renal failure; diabetes
• C. Asthma
• D. Hypertension

Answer: (A)

Acetaminophen is avoided when liver function is impaired or there is a known hypersensitivity, because the drug is processed by the liver and can cause severe hepatotoxicity in liver disease, and an immediate hypersensitivity reaction is an absolute contraindication. In addition, giving another dose within a short window after the patient has already taken acetaminophen (here, within 4 hours) is contraindicated to prevent exceeding the recommended dose and increasing risk of liver injury. Renal failure, asthma, and hypertension do not by themselves contraindicate acetaminophen use.