What is the management for a patient who ingested 80mg of Baclofen (a muscle relaxant) over 8 hours?

Management of Baclofen Overdose (80mg over 8 hours)

This patient requires immediate supportive care with close monitoring for CNS and respiratory depression, as baclofen overdose primarily causes sedation, respiratory depression, and potential cardiovascular instability that must be managed symptomatically since there is no specific antidote. 1

Immediate Assessment and Monitoring

• Assess level of consciousness and respiratory status immediately - baclofen causes dose-dependent CNS depression including sedation, somnolence, ataxia, and respiratory depression 1, 2
• Monitor vital signs continuously, particularly respiratory rate, oxygen saturation, blood pressure, and heart rate, as baclofen can cause cardiovascular depression 1
• Establish IV access and prepare for potential airway management if significant respiratory depression develops 1

Supportive Care Measures

• Provide respiratory support as needed - ranging from supplemental oxygen to mechanical ventilation depending on severity of respiratory depression 1, 3
• Maintain adequate hydration and hemodynamic support with IV fluids if hypotension develops 1
• Consider activated charcoal if presentation is within 1-2 hours of ingestion and airway is protected, though baclofen is rapidly absorbed 1
• Do NOT attempt rapid discontinuation - even in overdose, abrupt cessation can precipitate severe withdrawal syndrome 4

Specific Monitoring Parameters

• Monitor for excessive sedation and altered mental status - these are the most common manifestations of baclofen toxicity 1, 2
• Assess for muscle weakness which can be pronounced and dose-related 2
• Watch for seizures, particularly if the patient has underlying epilepsy or brain injury, as baclofen can lower seizure threshold 1
• Monitor oxygen saturation closely as baclofen may reduce mean overnight oxygen saturation even at therapeutic doses 3

Duration of Monitoring

• Observe for at least 12-24 hours given baclofen's relatively rapid absorption and elimination, with large intersubject variation 1
• Most adverse effects are transient and reversible with supportive care 2
• Symptoms should improve as drug is renally excreted unchanged - elimination may be prolonged in renal impairment 1, 2

Key Clinical Pitfalls

• There is NO specific antidote or reversal agent for baclofen overdose - management is entirely supportive 1, 5
• Do not use flumazenil - baclofen is a GABA-B agonist, not a benzodiazepine, and flumazenil will not reverse its effects 1, 6
• Avoid abrupt discontinuation even after overdose as withdrawal can cause seizures, psychic symptoms, and hyperthermia that may be more dangerous than the overdose itself 4, 2
• Patients with renal disease are at higher risk for prolonged toxicity and may require extended monitoring 2

Disposition

• Admit to monitored setting (ICU if severe respiratory depression, otherwise telemetry/step-down unit) for continuous observation 1, 2
• Discharge only after full resolution of CNS depression and return to baseline mental status with stable vital signs 2