250 - Baclofen Toxicity and Baclofen Withdrawal: Case Studies

Pt 1: A 71-y.o. male with ESRD on HD presented to the hospital complaining of persistent hiccups over the preceding few days. He was admitted and started on oral baclofen, 10 mg TID. After five doses, the medication was stopped as the patient became increasingly restless. Soon thereafter, an RRT was called for AMS. At that juncture, he was moving all extremities, following commands, and had a negative CTH. Hours later, the patient became unresponsive with sluggish pupils. He was then intubated and admitted to the ICU. 

Pt 2: A 42-y.o. male with chronic, complete C5 tetraplegia presented to the ED one day after a scheduled baclofen pump replacement endorsing full body spasms, and nausea. His pump was interrogated and deemed to be working appropriately, at his rate of 424.8 mcg/day. However, hours later, he sustained cardiac arrest and passed away. 

Discussions: Baclofen has long been used as an antispasmodic, but is also used off-label for treatment of hiccups. Established norms for off-label baclofen are understandably lacking, but typically the medication is dosed at 10 mg TID. The cases described herein characterize the risks associated with the medication at dangerously high or low doses. Indeed, there have been reports of baclofen toxicity in HD patients, since up to 90% of baclofen is filtered by the kidneys. Conversely, patients with spasticity are often treated with an intrathecal baclofen pump, which typically function for 5-7 years before being replaced. However, baclofen withdrawal can ensue if the pump and/or catheter malfunctions, which is crucial for providers to keep in mind.

Conclusions: Baclofen toxicity and withdrawal can present with serious side effects. Patients taking either oral or intrathecal baclofen must be monitored to prevent adverse events.