Pharmacology · single question
A 59-year-old male with hepatic cirrhosis requires extraction of tooth 3. Which postoperative analgesic should be avoided?
Show answer and explanation
Correct answer: B. Acetaminophen (Tylenol®)
Acetaminophen is metabolized in the liver to NAPQI, a hepatotoxic metabolite normally detoxified by glutathione. In hepatic cirrhosis, liver function is severely impaired and glutathione stores are depleted, leading to NAPQI accumulation and hepatotoxicity. Acetaminophen must be avoided or used at greatly reduced doses in cirrhosis. Ibuprofen carries GI/renal risks but can be used cautiously for short durations at low doses in compensated cirrhosis.
- A. INCORRECT. Hydromorphone is an opioid that requires dose reduction in liver disease but is not absolutely contraindicated in the same way acetaminophen is.
- B. CORRECT. Acetaminophen is converted to the hepatotoxic metabolite NAPQI in the liver. In cirrhosis, impaired liver function and depleted glutathione mean NAPQI accumulates, worsening liver damage. Acetaminophen is most definitively contraindicated in hepatic cirrhosis.
- C. INCORRECT. While ibuprofen carries risks in cirrhosis (GI bleeding, renal impairment), it can be used short-term at low doses cautiously. It is not THE most dangerous analgesic choice in this specific context.
- D. INCORRECT. Fentanyl (opioid) — while opioids require dose adjustment in liver disease, fentanyl can be used with caution. It is not the primary analgesic to 'avoid' in this context.