What are the risks and prognosis for an 8-year-old child who accidentally ingested a 100mg Losartan (angiotensin II receptor antagonist) tablet?

Management of Accidental Losartan Ingestion in an 8-Year-Old Child

An 8-year-old child who accidentally ingested a single 100mg losartan tablet is likely to be okay, but should be monitored for potential hypotension and electrolyte disturbances, and the Poison Control Center should be contacted immediately for guidance specific to this case.

Immediate Assessment and Action

1. Contact Poison Control Center immediately (800-222-1222)

   • Provide information about the medication, dosage (100mg), time of ingestion, and child's age and weight 1
   • Follow their specific recommendations for this case

2. Monitor vital signs

   • Blood pressure is the most critical parameter to monitor as hypotension is the primary concern
   • Heart rate and respiratory status should also be monitored

Risk Assessment

The primary risks of losartan ingestion in a child include:

• Hypotension: The most concerning potential effect, as losartan blocks angiotensin II receptors, causing vasodilation 2, 3
• Electrolyte disturbances: Particularly hyperkalemia
• Dizziness: Most commonly reported adverse effect of losartan 4

Severity Assessment

The severity of this ingestion can be assessed as follows:

1. Dose comparison to therapeutic pediatric dosing:

   • The FDA-approved pediatric dose of losartan is 0.7 mg/kg once daily (up to 50 mg) 2
   • For an average 8-year-old (approximately 25-30 kg), the therapeutic dose would be around 17.5-21 mg
   • The 100mg ingestion represents approximately 3-4 times the therapeutic dose

2. Expected clinical effects:

   • The pharmacokinetics of losartan are linear and dose-proportional 3
   • The active metabolite E3174 has a half-life of 6-9 hours 3
   • Maximum concentration is reached 1-2 hours after ingestion 3

Management Approach

1. Observation period

   • Monitor for at least 6 hours after ingestion, particularly focusing on blood pressure
   • The peak effect may occur within 1-2 hours of ingestion 3

2. Supportive care

   • If hypotension develops:
     • Place child in Trendelenburg position (legs elevated)
     • Administer IV fluids if needed
     • In severe cases that don't respond to fluids, vasopressors may be considered

3. Laboratory monitoring (if symptomatic)

   • Electrolytes (particularly potassium)
   • Renal function tests

4. When to seek emergency care

   • If the child develops hypotension, dizziness, fainting, or other concerning symptoms
   • If the child has pre-existing kidney disease or is taking other medications that might interact with losartan

Prognosis

The prognosis is generally good for a single accidental ingestion of 100mg losartan in an otherwise healthy child. Unlike some other antihypertensive medications, losartan has a relatively favorable safety profile 5, 4:

• It has a slower onset of action, making first-dose hypotension uncommon 5
• It has minimal effects on heart rate
• It does not typically cause central nervous system depression

Important Considerations

• No specific antidote exists for losartan overdose
• Do not induce vomiting as there is insufficient evidence that dilution or neutralization with water or milk is beneficial as a first aid measure 1
• Do not administer activated charcoal unless advised by poison control or emergency medical personnel 1

Prevention of Future Incidents

• Store all medications out of reach of children
• Use child-resistant containers
• Educate family members about medication safety

Remember that while this ingestion is concerning, a single tablet overdose in an otherwise healthy child typically has a good prognosis with appropriate monitoring and supportive care.