From the Guidelines
Patients with anuric renal failure receiving morphine for end-of-life care are at increased risk of developing myoclonic jerks due to the accumulation of neurotoxic metabolites such as morphine-3-glucuronide and normorphine. This is because morphine use in significant renal function impairment can result in opioid-induced neurotoxicity 1. When managing end-of-life pain in patients with anuric renal failure, consider using alternative opioids like:
- Hydromorphone
- Fentanyl, which are less likely to result in accumulation of active metabolites in renal failure 1
- Methadone, as it is primarily metabolized in the liver, but should only be used by experienced clinicians 1. Key considerations for morphine use in this context include:
- Reducing the dose by 50-75% and extending dosing intervals if morphine must be used
- Monitoring closely for signs of neurotoxicity, including myoclonus, confusion, sedation, and respiratory depression
- Optimizing hydration status within the goals of care, as dehydration can worsen opioid toxicity in renal failure. If myoclonic jerks develop, treatment options include reducing the morphine dose, rotating to a different opioid, or administering benzodiazepines to control the jerks.
From the FDA Drug Label
Renal Impairment: Morphine pharmacokinetics are altered in patients with renal failure The AUC is increased, and clearance is decreased and the metabolites, M3G and M6G, may accumulate to much higher plasma levels in patients with renal failure as compared to patients with normal renal function.
Renal Impairment: Morphine sulfate pharmacokinetics are altered in patients with renal failure. Clearance is decreased and the metabolites, M3G and M6G, may accumulate to much higher plasma levels in patients with renal failure as compared to patients with normal renal function Start these patients cautiously with lower doses of morphine sulfate injection and titrate slowly while carefully monitoring for side effects.
The FDA drug label does not answer the question about myoclonic jerks on morphine for end of life care in anuric renal failure.
From the Research
Anuric Renal Failure and Myoclonic Jerks on Morphine
- In patients with anuric renal failure, the use of morphine for end-of-life care may be problematic due to the increased risk of morphine toxicity and side effects such as myoclonic jerks 2, 3.
- Myoclonic jerks can occur in patients with renal failure, particularly in those with end-stage renal disease, and may be resolved with renal replacement therapy 4.
- The use of morphine in patients with renal failure is generally not recommended due to the increased risk of toxicity and side effects, and alternative opioids such as fentanyl or methadone may be safer options 2, 3, 5.
- In patients with end-stage heart failure and renal failure, fentanyl infusion may be an effective option for relieving dyspnea, and may be preferred over morphine due to its safer pharmacokinetic profile 6.
- The development of myoclonic jerks in patients with anuric renal failure who are receiving morphine for end-of-life care may be a sign of morphine toxicity, and alternative analgesics or dose adjustments may be necessary to prevent this complication 3.