What is the treatment for a gabapentin (Neurontin) overdose?

Treatment of Gabapentin Overdose

Gabapentin overdose is managed primarily with supportive care, as there is no specific antidote; hemodialysis should be considered in patients with severe toxicity (particularly coma requiring mechanical ventilation) who have renal impairment, though it is generally not recommended for patients with normal kidney function. 1, 2

Immediate Supportive Care

The cornerstone of management is standard resuscitation measures, as gabapentin toxicity primarily causes CNS depression 1:

• Establish and maintain airway patency with bag-mask ventilation if needed, progressing to endotracheal intubation for patients unable to protect their airway 3
• Support breathing and oxygenation to prevent hypoxemia-related tissue injury 3
• Treat hypotension with standard fluid resuscitation and vasopressors as indicated 3
• Monitor for and manage cardiac dysrhythmias according to standard protocols 3

Clinical Presentation and Expected Symptoms

Acute gabapentin overdoses up to 49 grams have been reported with the following manifestations 1:

• Double vision and slurred speech 1
• Drowsiness, lethargy, and sedation 1
• Ataxia and dizziness 1
• Diarrhea 1
• In severe cases with renal failure: coma (which may resolve with dialysis) 1

All reported patients with isolated gabapentin overdose and normal renal function have recovered with supportive care alone 1, though one fatal case has been documented in the literature with a postmortem gabapentin level of 88 μg/mL 4.

Critical Assessment for Co-Ingestions

Always evaluate for co-ingestions, as these significantly increase morbidity and mortality risk 5:

• Opioids: This combination creates dangerous respiratory depression and is the primary concern for fatal outcomes 5
• Benzodiazepines: Cumulative sedative effects increase risk of respiratory compromise 5
• Other CNS depressants: Additive effects on mental status and respiratory drive 5
• Administer naloxone immediately if opioid co-ingestion is suspected, regardless of gabapentin involvement 3

Role of Hemodialysis

The EXTRIP workgroup provides specific guidance on extracorporeal treatment 2:

For patients with normal kidney function:

• The workgroup suggests against performing hemodialysis in addition to standard care (weak recommendation, very low quality of evidence) 2
• Gabapentin is highly dialyzable with clearance >150 mL/min and elimination half-life <5 hours during hemodialysis 2
• However, severe toxicity, mortality, and sequelae are rare with standard care alone, and no clear clinical benefit from dialysis could be identified 2

For patients with decreased kidney function AND coma requiring mechanical ventilation:

• The workgroup suggests performing hemodialysis in addition to standard care (weak recommendation, very low quality of evidence) 2
• Gabapentin elimination half-life increases dramatically from 5-9 hours in normal renal function to 132 hours in dialysis patients 6
• Renal impairment causes linear increases in plasma gabapentin concentrations as clearance is directly proportional to creatinine clearance 6

Poison Control Consultation

Contact your regional poison center at 1-800-222-1222 (in the United States) for expert toxicology guidance on specific cases 3, 1. These centers are staffed by board-certified medical and clinical toxicologists with specialized training in poisoning resuscitation 3.

Common Pitfalls to Avoid

• Do not assume gabapentin alone is benign: While generally safe, severe toxicity can occur, particularly in renal impairment 6
• Do not miss co-ingestions: The majority of serious morbidity and mortality involves polysubstance overdoses, especially with opioids 5, 7
• Do not overlook renal function: Patients with any degree of renal impairment are at substantially higher risk for prolonged toxicity 6, 2
• Do not delay supportive care while considering dialysis: Standard resuscitation takes priority 3, 1

Monitoring and Disposition

• Observe patients until mental status normalizes and they can protect their airway 1
• In patients with renal impairment, expect prolonged recovery times (elimination half-life up to 132 hours) and consider extended monitoring or admission 6
• Drug level monitoring is rarely available or clinically useful for acute management, but may help confirm diagnosis in unclear cases 6