Can I use baclofen (GABA receptor agonist) for back spasms in patients with End-Stage Renal Disease (ESRD) on hemodialysis?

Baclofen Should Be Avoided in Patients with ESRD on Hemodialysis

Baclofen is contraindicated in patients with end-stage renal disease (ESRD) on hemodialysis due to high risk of severe neurotoxicity, even at low doses. 1

Risk of Baclofen Toxicity in ESRD

• Baclofen is primarily excreted via the kidneys, making patients with severely reduced kidney function at high risk for toxicity 1
• Even a single dose of baclofen (as low as 25mg) can cause severe neurotoxicity in ESRD patients 2
• Patients on hemodialysis who take baclofen commonly develop:
  • Altered mental status and encephalopathy 3
  • Decreased muscle tone and hypotonia 3
  • Respiratory depression in severe cases 4
  • Abdominal pain (reported in multiple cases) 4
  • Hemodynamic instability 1

Evidence Against Baclofen Use in ESRD

• Multiple case reports document severe toxicity in hemodialysis patients after even small doses of baclofen 3, 2, 5
• A comprehensive review of 16 cases found that most ESRD patients developed toxic symptoms shortly after initiating even low-dose baclofen therapy 4
• Experts recommend avoiding baclofen use in patients with severely reduced kidney function (eGFR <30 mL/min/1.73m²) or those on renal replacement therapy 1

Alternative Options for Muscle Spasms in ESRD

• For patients with ESRD requiring treatment for muscle spasms, gabapentin may be considered as an alternative, though it requires dose adjustment for dialysis patients 6
• Gabapentin has been shown effective in ESRD patients at doses of 100-300mg after dialysis three times weekly 6
• A double-blind, placebo-controlled trial showed significant improvement with gabapentin 400mg twice weekly after hemodialysis sessions 6

Management of Baclofen Toxicity if it Occurs

• If baclofen toxicity develops in an ESRD patient, urgent hemodialysis is the recommended treatment 3
• Early hemodialysis (within 48 hours of symptom onset) results in shorter recovery time compared to supportive care alone 4
• Multiple hemodialysis sessions may be required for complete resolution of symptoms 3
• Note that there may be a lag of several hours between hemodialysis and improvement in mental status 4

Clinical Pearls and Pitfalls

• Baclofen toxicity is an under-diagnosed condition, especially in patients with renal dysfunction 3
• Always review medication lists carefully in ESRD patients presenting with unexplained altered mental status or hypotonia 5
• Consider baclofen toxicity in the differential diagnosis for ESRD patients with encephalopathy even if they've only taken a single dose 2
• Healthcare professionals need more education about the risks of baclofen in kidney-impaired patients 2