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Pharmacology · patient case with 2 questions

Liver disease and a history of substance use

Patient: Male, 51 years old

Chief Complaint: Presents after surgical extraction of two mandibular molars and asks what to take for the pain.

Background: Hepatitis B and hepatitis C. Long history of heavy alcohol use, now six months abstinent. Past opioid use disorder, currently in recovery and attending a programme.

Vital Signs: BP 128/80 mmHg · HR 78 bpm

Laboratory: Elevated transaminases. INR 1.6. Platelets 118,000/µL.

Question 1

Which analgesic regimen should NOT be prescribed to this patient every four to six hours?

  1. Acetaminophen 500 mg with ibuprofen 600 mg
  2. A short course of a non-opioid with cold application and elevation
  3. Scheduled ibuprofen 400 mg alone for 48 hours
  4. Acetaminophen 325 mg alone, capped at 2 g per day
Show answer and explanation

Correct answer: A. Acetaminophen 500 mg with ibuprofen 600 mg

  • A. CORRECT. This combination is the wrong choice on BOTH counts in a patient with chronic hepatitis and alcohol history. Acetaminophen 500 mg every four hours reaches 3 g daily, well above the 2 g ceiling advised in liver disease, and chronic alcohol use induces CYP2E1 and depletes glutathione, so more of the hepatotoxic metabolite NAPQI is produced and less is detoxified. Ibuprofen 600 mg adds the other hazard: NSAIDs in advanced liver disease raise the risk of variceal and mucosal bleeding, and can precipitate hepatorenal syndrome by removing the prostaglandin support that maintains renal perfusion. The raised INR and low platelets make the bleeding risk concrete.
  • B. Non-pharmacological measures alongside a limited non-opioid course is exactly the right approach for a patient with both hepatic impairment and a history of opioid use disorder.
  • C. Brief scheduled ibuprofen carries less cumulative risk than the combination, though in a patient with an INR of 1.6 and thrombocytopenia it still warrants caution and medical consultation.
  • D. Acetaminophen remains the preferred analgesic in liver disease provided the total daily dose is REDUCED, usually to 2 g or less, and the duration is short. This is the safe version of the same drug.

Note: The recall listed hydrocodone and tramadol as the other options; both are also poor choices here given the recovery history. The keyed answer stands, but note the reason is hepatic and bleeding risk rather than dosing frequency alone.

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Question 2

Given his history of opioid use disorder in recovery, which medication is most important to avoid?

  1. Fentanyl
  2. Ibuprofen
  3. Amoxicillin
  4. Acetaminophen
Show answer and explanation

Correct answer: A. Fentanyl

  • A. CORRECT. FENTANYL is a high-potency synthetic mu agonist with rapid onset — precisely the profile most likely to trigger relapse in a patient in recovery, and the one most associated with overdose. Prescribing any opioid to a patient in recovery requires a compelling indication, the shortest possible course, and ideally coordination with the treating physician or recovery programme. Fentanyl specifically should be avoided in the outpatient dental setting for this patient.
  • B. Ibuprofen is a non-opioid with no abuse liability. It carries its own risks here from the liver disease and bleeding parameters, but not from the addiction history.
  • C. Amoxicillin is an antibiotic with no relevance to substance use risk.
  • D. Acetaminophen has no abuse potential. Its constraint in this patient is hepatic dose limitation.

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Practice patient cases Pharmacology study notes