Dose Conversions Practice Test

A 52-year-old male (weight 90 kg) with chronic hepatitis C and cirrhosis is being treated for anxiety with lorazepam, but due to excessive sedation the team plans to use a reduced dose. Medical history: cirrhosis (Child-Pugh class C), anxiety. Current medications: spironolactone 100 mg daily, furosemide 40 mg daily, lactulose 20 g three times daily. Labs: AST 110 U/L (normal 10–40), ALT 95 U/L (normal 7–56), total bilirubin 3.2 mg/dL (normal 0.2–1.2), albumin 2.6 g/dL (normal 3.5–5.0). If the usual lorazepam dose is 1 mg by mouth every 8 hours and the plan is to reduce the total daily dose by 50% due to hepatic impairment, determine the appropriate total daily dose for this patient.

A 72-year-old female (weight 60 kg) with chronic pain is being transitioned from oral morphine to a transdermal fentanyl patch due to poor adherence. Medical history: osteoarthritis, chronic low back pain, mild CKD. Current medications: morphine immediate-release 30 mg by mouth every 6 hours, docusate 100 mg twice daily. Labs: serum creatinine $1.0\ \text{mg/dL}$ (normal 0.6–1.1), AST/ALT within normal limits. Using the common conversion approximation that a fentanyl patch $25\ \text{mcg/hour}$ is roughly equivalent to $60\ \text{mg/day}$ of oral morphine, what is the most appropriate fentanyl patch strength for an equivalent total daily opioid dose?