LD₅₀ for Bupropion in Children
There is no established LD₅₀ (lethal dose 50) for bupropion in children, as this value is not ethically determined in humans and pediatric-specific data do not exist. However, based on available evidence, lethal doses in adults have been estimated at less than 10 grams, with fatalities reported at doses as low as 23 grams, and serious toxicity including seizures and death can occur at much lower doses in the pediatric population 1, 2, 3.
What We Know About Lethal Doses
Adult Data (Limited Applicability to Children)
- Fatal overdoses in adults have been documented with bupropion blood levels of 4.0-4.2 mg/L (parent drug) and total metabolite levels of 15-16.6 mg/L 2
- Estimated lethal doses in adult cases were less than 10 grams based on history 2
- One fatal case involved a 23-gram ingestion 3
- Postmortem concentrations in fatal cases ranged from 3.1 to >20 mg/L 4
Critical Pediatric Considerations
Children are NOT small adults when it comes to bupropion toxicity. The FDA label explicitly states that safety and effectiveness in the pediatric population have not been established 1.
Pediatric Toxicity Profile
Dose-Dependent Severe Toxicity
Bupropion overdose in children presents with significantly more severe manifestations than in exploratory ingestions:
Adolescents (13-17 years) vs. Younger Children (<13 years):
- Seizure risk: 40.8% vs. 3.2% (p < 0.001) 5
- Composite endpoint (seizure/hypotension/intubation): 42.9% vs. 6.5% (p < 0.001) 5
- Status epilepticus has been reported even in infants, leading to cardiopulmonary arrest and hypoxic-ischemic encephalopathy 6
Comparative Lethality
When compared to SSRIs in adolescent overdoses, bupropion demonstrates:
- Death rate: 0.23% vs. 0% for SSRIs (p < 0.001) 7
- Serious outcomes: 58.1% vs. 19% for SSRIs (p < 0.001) 7
- Seizures: 27.0% vs. 8.5% for SSRIs (p < 0.001) 7
- Need for CPR: 0.51% vs. 0.01% for SSRIs (p < 0.001) 7
- Intubation required: 4.9% vs. 0.3% for SSRIs (p < 0.001) 7
Clinical Implications
Why No Specific LD₅₀ Exists
- Ethical constraints: LD₅₀ studies cannot be performed in humans, especially children
- Individual variability: Seizure threshold, metabolism, and organ function vary significantly
- Formulation differences: Sustained-release preparations may result in delayed absorption and prolonged toxicity 4
Overdose Manifestations (FDA Label)
The FDA reports that overdoses of up to 30 grams or more have been documented, with seizures occurring in approximately one-third of all cases 1. Other serious reactions include:
- Hallucinations (28.6% in pediatric overdoses) 7
- Loss of consciousness
- Sinus tachycardia and cardiac conduction disturbances
- Clonus, myoclonus, hyperreflexia 1
Critical Pitfall
Any bupropion overdose in a child should be treated as potentially life-threatening, regardless of reported dose, because:
- Seizures can be delayed beyond 6 hours 5
- Status epilepticus can occur even with relatively small ingestions in young children 6
- Cardiopulmonary arrest may follow seizure activity 6, 3
Bottom Line
There is no safe way to predict a lethal dose in an individual child. The absence of a pediatric LD₅₀ reflects both ethical research limitations and the dangerous unpredictability of bupropion toxicity in this population. Given that bupropion demonstrates significantly higher morbidity and mortality compared to alternative antidepressants in pediatric overdose 7, 8, and that adolescent suicide attempts are often impulsive using medications of convenience 7, prescribers should carefully weigh these overdose risks when considering bupropion for any pediatric patient.