Baclofen Overdose Treatment
Immediately secure the airway with endotracheal intubation if the patient is obtunded, perform gastric lavage (do NOT induce emesis in obtunded patients), maintain adequate respiratory support, and provide intensive supportive care—there is no specific antidote for baclofen overdose. 1
Initial Management Algorithm
Airway and Decontamination
- In alert patients: Induce emesis followed by gastric lavage to empty the stomach promptly 1
- In obtunded patients: Secure the airway with a cuffed endotracheal tube BEFORE beginning lavage—never induce emesis in these patients 1
- Maintain adequate respiratory exchange throughout treatment 1
Supportive Care Priorities
- Do NOT use respiratory stimulants despite respiratory depression 1
- Provide intensive care monitoring for cardiovascular and neurological complications 2, 3
- Monitor for bradycardia and hypotension, which are characteristic of baclofen overdose (not anticholinergic syndrome as previously thought) 4
Clinical Presentation to Expect
The overdose manifests with:
- Vomiting, muscular hypotonia, and drowsiness 1
- Accommodation disorders and coma 1
- Respiratory depression requiring ventilatory support 1
- Seizures 1
- Bradycardia and hypotension (not tachycardia) 4
- Profound coma with brainstem dysfunction that can mimic brain death 5
Special Considerations for Intrathecal Baclofen Overdose
CSF Drainage Approach
- Perform lumbar puncture with CSF drainage to lower baclofen levels in the CSF—this classical approach has proven successful and is safer than pharmacological antidotes 4
- Sequential lumbar punctures or continuous lumbar drains may be necessary 2
- Immediate cessation of baclofen delivery through the pump system 3
Antidotes: NOT Recommended
- Physostigmine is NOT consistently effective and carries major side-effects—the doubtful antidotal benefits must be weighed against significant risks 4
- Flumazenil is not usually advised 2
- Conservative symptomatic treatment in an intensive care environment is superior to antidote therapy 4
Critical Pitfall: Baclofen Withdrawal Syndrome
The Paradoxical Risk
After treating the acute overdose, you MUST be vigilant for severe baclofen withdrawal syndrome, which can be life-threatening and occurs when baclofen levels drop precipitously in chronic users. 6
Withdrawal Presentation
- Hallucinations, delirium, and altered mental status 7, 8
- High fever, seizures, and tachycardia 7
- Rebound spasticity and muscle rigidity 7, 8
- Rhabdomyolysis and multiorgan failure (especially with intrathecal baclofen) 7
- Symptoms typically evolve over 1-3 days but may become fulminant 7
Managing Withdrawal After Overdose
- Reinstitution of baclofen therapy is the primary treatment for withdrawal 8
- In acute-on-chronic overdose cases, withdrawal symptoms may not be recognized until days later—maintain high suspicion 6
- Restoration of ITB delivery using the previous dosing schedule for short-duration withdrawal, or 10-20 mg every 6 hours for longer-duration withdrawal 2
- Low-dose propofol or benzodiazepines may be used in selected cases 3
Monitoring and Diagnostic Workup
Essential Evaluations
- Pump interrogation and reservoir volume assessment (for intrathecal systems) 2
- Catheter imaging to rule out mechanical issues 2
- Rising creatine kinase levels indicating rhabdomyolysis 2
- Electroencephalography may show burst suppression pattern in severe cases 5
- Imaging results are usually normal and may be misleading 5
Prognosis
The prognosis can be excellent even in severe cases with profound coma, provided the overdose is recognized early and appropriate supportive measures are instituted. 5 Recovery may take several days with intensive supportive care 6, 5