Baclofen pump toxicity and withdrawl

30 Mar

Baclofen is a gamma-aminobutyric acid (GABA) derivative, an inhibitory neurotransmitter that functions ultimately to relieve muscle spasticity.

Conditions in which you might see it used:  cerebral palsy, spinal cord injury, generalized dystonia, multiple sclerosis, intractable hiccups

How it’s given: oral or IV, topical creams, intrathecal via implantable device (baclofen pump)

Abrupt discontinuation of intrathecal baclofen has resulted in

  • high fever,
  • altered mental status,
  • itching,
  • exaggerated rebound spasticity,
  • muscle rigidity,
  • rhabdomyolysis,
  • multiple organ-system failure,
  • and death.

Typically, neurosurgery or a pain specialist (anesthesia) can be consulted to interrogate the pump. Treatment involves supportive care, administration of oral or enteral baclofen, and benzodiazepines.

Toxicity results in

  • muscular hypotonia,
  • areflexia,
  • somnolence,
  • respiratory depression,
  • bradycardia,
  • hypotension,
  • temperature instability,
  • coma. 

Measuring serum levels are not always reliable- the diagnosis is clinical.

Treatment involves supportive measures (IV fluids, vasopressors for hypotension, airwary support), discontinuation of the pump (as well as draining the reservoir to stop the motor), withdraw fluid/CSF from the catheter access port (to extract any baclofen that is still in the catheter or adjacent to it), and consideration of physostigmine (be aware of side effects of bradycardia and increased airway secretions).

 

Submitted by K Estes

 

References: Yeh RN1, Nypaver MM, Deegan TJ, Ayyangar R. Baclofen toxicity in an 8-year-old with an intrathecal baclofen pump. J Emerg Med. 2004 Feb;26(2):163-7. PMID: 14980337.

Uptodate.com

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: