Severe Bradyarrhythmia and Reduced Cardiac Output Due to Oral Baclofen Withdrawal in a 24-Year Old Man: A Case Report.

BACKGROUND Baclofen is a selective gamma-aminobutyric acid (GABA) receptor agonist and muscle relaxant prescribed to treat spasticity and muscle pain and is used off-label to treat alcohol use disorder and gastroesophageal reflux disease. Baclofen withdrawal syndrome is a rare condition that presents with abnormal cardiac rhythm and function. This report describes the case of a 24-year-old man who presented with polypharmacy overdose, including baclofen, who subsequently showed features of baclofen withdrawal, requiring baclofen reintroduction. CASE REPORT A 24-year-old man was admitted to the Intensive Care Unit after suspected polypharmacy overdose of baclofen, escitalopram, and ethanol. Thirty-six hours later, the patient developed severe bradyarrhythmia and associated reduced cardiac output/arrest, requiring inotropic and vasopressor support. Extensive cardiac workup showed no abnormalities that could explain the symptoms; however, the patient had persistent episodes of severe bradyarrhythmia and loss of cardiac output. Given the lack of improvement, potential baclofen withdrawal was hypothesized for the episodes of bradycardia and low cardiac output. Low-dose baclofen was therefore reintroduced. After 36 h of reintroducing baclofen, all episodes of severe bradyarrhythmia and low cardiac output resolved. The patient went on to make a full recovery, with ongoing low-dose baclofen therapy. This case highlights that, even in the possible setting of baclofen toxicity, baclofen withdrawal must also be considered as a potential cause of bradycardia and low cardiac output leading to hypotension. CONCLUSIONS Baclofen withdrawal can lead to life-threatening cardiac depression. Re-introduction of baclofen might be therapeutic in the management of these cases.