I took seven pregabalin tablets; what is the appropriate emergency management?

Emergency Management of Pregabalin Overdose (Seven Tablets)

Immediate supportive care with airway management and monitoring is the cornerstone of pregabalin overdose management, as there is no specific antidote. 1

Immediate Assessment and Stabilization

Establish airway patency immediately and provide bag-mask ventilation if respiratory depression is present, followed by endotracheal intubation if airway reflexes are compromised. 2, 3 The most commonly reported adverse events in pregabalin overdose include reduced consciousness, depression/anxiety, confusional state, agitation, and restlessness 1. Seizures and heart block have also been reported, though less commonly 1.

Critical Initial Steps

• Contact your regional Poison Control Center immediately (1-800-222-1222 in the US) for expert toxicology guidance and real-time management recommendations. 2, 3
• Monitor vital signs continuously, including respiratory rate, oxygen saturation, heart rate, blood pressure, and cardiac rhythm. 1, 4
• Assess level of consciousness using a standardized scale and monitor for progression to coma. 1, 5

Gastrointestinal Decontamination

If the patient presents within 1-2 hours of ingestion and has intact airway reflexes, consider gastric lavage followed by activated charcoal (1-2 g/kg PO or nasogastrically; adolescent/adult dose: 50-100 g). 2, 1, 4 However, if airway protective reflexes are impaired, the risk of administering activated charcoal may outweigh the benefits due to aspiration risk. 2

Important Caveats

• Do not induce emesis or perform gastric lavage if the patient has altered mental status or compromised airway reflexes. 1
• Activated charcoal is most effective when given within 1 hour of ingestion, with diminishing benefit thereafter. 2

Dose-Toxicity Relationship

The severity of pregabalin poisoning correlates with dose, though significant interindividual variability exists 5:

• Below 20 mg/kg: 83% of patients experience only mild poisoning (drowsiness, confusion, apathy). 5
• Above 20 mg/kg: Risk of moderate-to-severe toxicity increases significantly (median dose for significant toxicity: 46.7 mg/kg). 5
• Most pregabalin poisonings are benign, though coma and convulsions occasionally occur. 5

Calculate the patient's dose in mg/kg to stratify risk: if seven tablets equals 2,100 mg (assuming 300 mg tablets) in a 70 kg adult, this represents 30 mg/kg—placing the patient at higher risk for significant toxicity. 5

Enhanced Elimination

Pregabalin can be removed by hemodialysis, with standard procedures achieving approximately 50% clearance in 4 hours. 1 However, hemodialysis should be reserved for severe poisoning with life-threatening symptoms (profound CNS depression, refractory seizures, cardiovascular instability) or in patients with renal impairment where drug elimination is compromised. 1, 4

Indications for Hemodialysis

• Severe CNS depression approaching coma 1
• Refractory seizures 1
• Cardiovascular instability (heart block, severe bradycardia) 1
• Renal impairment (creatinine clearance <30 mL/min) where pregabalin accumulation is expected 3

Supportive Care and Monitoring

General supportive care is the mainstay of treatment, including:

• Intravenous hydration to maintain adequate renal perfusion and enhance drug elimination. 4
• Supplemental oxygen to maintain SpO2 >94%. 4
• Continuous cardiac monitoring for heart block or arrhythmias. 1
• Seizure precautions and benzodiazepines (lorazepam 0.1 mg/kg IV or diazepam 0.1-0.3 mg/kg IV) if seizures occur. 2
• Monitor for respiratory depression and be prepared to provide mechanical ventilation if needed. 2, 1

Special Considerations

Assess for polypharmacy overdose, particularly co-ingestion with other CNS depressants (benzodiazepines, opioids, alcohol), as pregabalin is frequently misused in combination with other substances. 3, 6 Deaths have been reported with lone pregabalin overdose but are more common in combination with other CNS depressants 1, 6.

High-Risk Populations

• Patients with substance use disorders are at higher risk for intentional overdose and co-ingestion. 6
• Elderly patients have longer elimination half-lives, increasing risk for prolonged toxicity. 3
• Patients with renal impairment (CrCl <30 mL/min) are at higher risk due to drug accumulation. 3

Expected Clinical Course

Most pregabalin poisonings result in minor toxicity (drowsiness 62%, confusion 29%, apathy 24%) that resolves with supportive care alone. 5 The plasma half-life of pregabalin is approximately 6 hours in patients with normal renal function 7, so symptoms typically resolve within 24-48 hours with adequate supportive care. 5

Disposition

• Admit all patients with moderate-to-severe toxicity (altered mental status, respiratory depression, seizures, cardiac conduction abnormalities) to a monitored setting. 1, 5
• Patients with mild symptoms and normal vital signs after 6-8 hours of observation may be medically cleared, but psychiatric evaluation is mandatory for intentional overdose. 5
• Follow up at least monthly if chronic pregabalin misuse is suspected, and screen for substance use disorders. 6

Common Pitfalls to Avoid

• Never assume pregabalin overdose is benign without assessing dose and monitoring for at least 6-8 hours, as severe toxicity can develop. 5
• Do not administer flumazenil, as pregabalin is not a benzodiazepine and flumazenil has no role in management. 2
• Do not delay contacting Poison Control—expert guidance can prevent complications and guide disposition decisions. 2, 3
• Do not discharge patients with intentional overdose without psychiatric evaluation, as pregabalin misuse is associated with substance use disorders. 6