Management of Accidental 20mg Fluoxetine Ingestion in a 10-Year-Old
A single 20mg fluoxetine ingestion in a 10-year-old child requires observation only, with no gastric decontamination or emergency treatment needed, as this dose is well below the threshold for significant toxicity. 1
Immediate Risk Assessment
- The ingested dose of 20mg represents approximately 0.5-0.7 mg/kg for a typical 10-year-old (assuming 30-40kg body weight), which is far below doses associated with serious toxicity 1
- In a large study of 120 pediatric fluoxetine exposures, children ingesting 20mg (median dose 2.26 mg/kg) developed only mild symptoms in 3.3% of cases, with no major adverse effects reported 1
- Fluoxetine has a significantly wider margin of safety compared to tricyclic antidepressants, making it relatively benign in overdose situations 2, 3
Expected Clinical Course
Most children remain completely asymptomatic after ingesting 20mg of fluoxetine. 1, 4
Possible mild symptoms that may develop within the first 24 hours include:
- Sinus tachycardia (heart rate ≥100 bpm) 5, 4
- Drowsiness or mild sedation 5
- Mild psychomotor agitation 3
- Nausea or vomiting 5
- Tremor 5
These symptoms, if they occur, are typically minor and self-limited, resolving within 24-48 hours without intervention 5, 4
Management Protocol
No gastric decontamination (activated charcoal, gastric lavage) is indicated for a 20mg ingestion. 1
Observation Strategy:
- Monitor vital signs (heart rate, blood pressure, temperature) for 4-6 hours post-ingestion 5, 4
- Observe for the mild symptoms listed above 5
- Contact your regional poison control center (1-800-222-1222 in the US) for case-specific guidance and follow-up recommendations 2
Supportive Care Only:
- Maintain adequate hydration 5
- Provide reassurance to the child and family 1
- No specific antidote or pharmacological intervention is required 5
When to Seek Emergency Care
While unlikely with a 20mg dose, seek immediate medical attention if the child develops:
- Seizure activity 6
- Altered mental status beyond mild drowsiness 3
- Cardiac arrhythmias beyond simple sinus tachycardia 5
- Signs of serotonin syndrome (confusion, agitation, muscle rigidity, fever, autonomic instability) - though this is extremely rare with fluoxetine alone 2
Important Caveats
- The vast majority (92%) of pediatric fluoxetine exposures involve doses of 60mg or below, and these consistently result in no or minimal effects 1
- Even massive ingestions (up to 43 mg/kg) in young children have resulted in complete recovery with supportive care alone 3
- Rare genetic polymorphisms in CYP2D6 can impair fluoxetine metabolism, but this would only become clinically relevant with chronic dosing or much larger acute ingestions 6
- The long half-life of fluoxetine means that if symptoms were to develop, they would emerge gradually over 6-24 hours rather than immediately 2