Intrathecal baclofen toxicity in a patient with acute kidney injury

A 9-year old male patient with a past medical history of congenital cytomegalovirus (CMV) infection and spastic quadriplegic cerebral palsy with an intrathecal baclofen pump was admitted to a tertiary care hospital with respiratory depression and unresponsiveness for approximately two days. He had a recent two-week hospital stay for respiratory failure due to pneumonia. After being prescribed antibiotics and being sent home, he had developed copious diarrhea. On readmission, he was found to be dehydrated and in acute renal failure. A physical exam revealed hypotonia throughout, in a patient who typically had spasticity with contractures. The Pediatric Rehabilitation Medicine service was consulted for possible baclofen toxicity. Some signs and symptoms of baclofen toxicity include respiratory depression, seizures, CNS depression, hypotonia, hypotension, absent deep tendon reflexes, lethargy, ataxia, and cardiac arrhythmias. His intrathecal baclofen (ITB) dose was reduced, and signs/symptoms of ITB overdose began to resolve. As renal function improved, spasticity returned, necessitating increase in ITB dosing toward the premorbid dose.