UMEM Educational Pearls

Category: Toxicology

Title: Baclofen clearance: hemodialysis or kidneys?

Keywords: baclofen overdose, hemodialysis, renal elimination (PubMed Search)

Posted: 8/20/2020 by Hong Kim, MD
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Baclofen is a presynaptic GABA-B receptor agonist in the spinal cord that is primarily used for muscle spasms/spasticity. In large overdose, baclofen can produce CNS depression, respiratory depression, bradycardia/hypotension, hypothermia, seizure and coma.

Baclofen is primarily eliminated by the kidney. In patients with end-stage kidney disease/acute kidney failure, hemodialysis (HD) has been used to enhance baclofen clearance. However, it is unclear if there is a benefit of using HD in patients with normal kidney function. 

In a recently published case report, HD was implemented in an attempt to shorten the anticipated prolonged ICU course. 

Case: 14 year old (51 kg) woman ingested 60 tablets of baclofen (20 mg tablets)

Her symptoms were:

  • Coma/CNS depression
  • Tonic-clonic seizure
  • Transient hypotension (95/47 mmHg – resolved with IV fluids)
  • Flaccid extremities
  • Initially intubated for airway protection --> no spontaneous breathing on mech. ventilation.

Baclofen level: 882 ng/mL (therapeutic range: 80 – 400 ng/mL)

Baclofen clearance from hemodialysis vs. urine

  • 24 hour urine output: 2810 mL --> total baclofen urinary elimination: 42 mg
  • 3 hours of HD #1: 3.05 mg removed. Total of 3 HD session performed.

Patient’s mental status improved on hospital day 6 and was extubated. She was discharged to psychiatry on hospital day 14.

 

 Conclusion:

  • Although this is a single case report, it appears that hemodialysis does not remove baclofen effectively.

References

Lee VR et al. Removal of baclofen with hemodialysis is negligible compared to intact kidney excretion in a pediatric overdose: a case report. Clin Toxicol. 2020

https://doi.org/10.1080/15563650.2020.1795188