American Board of Internal Medicine (ABIM) Certification Practice Exam

What opioid should be avoided in patients with kidney failure?

1. Fentanyl

2. Oxycodone

3. Morphine

4. Hydromorphone

The correct answer is: Morphine

In patients with kidney failure, morphine should be avoided due to its accumulation in the body resulting from impaired renal clearance. Morphine is metabolized primarily by the liver, but its active metabolites—morphine-6-glucuronide and morphine-3-glucuronide—are excreted by the kidneys. In patients with kidney dysfunction, these metabolites can accumulate, potentially leading to increased sedation, respiratory depression, and other adverse effects. While other opioids such as fentanyl, oxycodone, and hydromorphone may still be used in patients with renal impairment, they also require careful consideration of dosing and monitoring. Fentanyl, for instance, is primarily metabolized by the liver and does not accumulate in the same manner as morphine when renal function is compromised. Oxycodone is also cleared by the liver, though monitoring is still prudent due to the risk of accumulation in severe renal impairment. Hydromorphone can still be used, but dosing adjustments may be necessary depending on renal function. Thus, due to the risk of increased side effects from the accumulation of its metabolites, morphine is the opioid that should be avoided in patients with kidney failure.