What is the recommended dose of atropine (antimuscarinic agent) for pediatric patients?

Atropine Dosing in Pediatric Patients

For symptomatic bradycardia in children, administer atropine 0.02 mg/kg IV/IO, with a minimum single dose of 0.1 mg and maximum single dose of 0.5 mg for children (1.0 mg for adolescents), which can be repeated every 5 minutes up to a maximum total dose of 1 mg for children and 2 mg for adolescents. 1, 2

Standard Dosing by Clinical Indication

Symptomatic Bradycardia

• Initial dose: 0.02 mg/kg IV/IO 1, 2
• Minimum single dose: 0.1 mg for children 1, 2
• Maximum single dose: 0.5 mg for children, 1.0 mg for adolescents 1, 2
• Repeat interval: Every 5 minutes as needed 1
• Maximum total dose: 1 mg for children, 2 mg for adolescents 1

The American Heart Association emphasizes that oxygenation and ventilation are the essential first maneuvers before considering atropine, as hypoxia-induced bradycardia typically responds to these interventions alone. 1 If bradycardia persists despite adequate oxygenation, epinephrine is actually the drug of choice, not atropine. 1

Rapid Sequence Intubation (RSI) Premedication

• Dose: 0.01-0.02 mg/kg IV/IO 1
• Administer before sedative/anesthetic and paralytic agents 1

Important caveat: The 2015 American Heart Association guidelines removed the minimum dose requirement when atropine is used as premedication for emergency intubation, allowing 0.02 mg/kg without a minimum. 1 This represents a shift from older practice patterns, as research has debunked the myth that doses below 0.1 mg cause paradoxical bradycardia in children. 3

Neonatal Dosing

• Dose: 0.01-0.03 mg/kg IV/IO 1
• No minimum dose required per current American Heart Association guidelines 1
• The historical 0.1 mg minimum dose requirement was eliminated after evidence demonstrated that 0.02 mg/kg without a minimum is both effective and safe 1
• A 2015 study definitively showed that atropine doses less than 0.1 mg (mean 40.9 µg) do not cause bradycardia in young infants, with zero incidence of bradycardia observed 3

Anticholinesterase/Organophosphate Poisoning

• Initial dose: 0.02-0.05 mg/kg IV (can use up to 0.05 mg/kg) 1, 4
• Maximum single dose: Typically 2-3 mg 4
• Repeat as needed for clinical effect based on muscarinic symptoms 1, 4

For nerve agent intoxication specifically, the initial dose should be 0.02 mg/kg for children, but cumulative doses may need to be substantially higher. 5 The American Society of Anesthesiologists notes that adult patients may require 10-20 mg in the first 2-3 hours, and up to 50 mg in 24 hours before full muscarinic antagonism appears. 5 Children symptomatic of nerve agent poisoning will likely need both supraphysiologic doses and frequent re-dosing. 6

Critical consideration for organophosphate poisoning: Atropine must be combined with oximes (pralidoxime) to address nicotinic receptor dysfunction and respiratory muscle paralysis, as atropine alone has minimal effect on these symptoms. 5, 4

Alternative Routes When IV/IO Access Unavailable

Endotracheal Administration

• Neonates: 0.01-0.03 mg/kg 1
• Children and adolescents: 0.03-0.06 mg/kg 1
• Follow with or dilute in saline flush (1-5 mL) based on patient size 1

FDA-Approved Dosing

The FDA label states that dosing in pediatric populations has not been well studied, but the usual initial dose is 0.01 to 0.03 mg/kg. 7 This aligns with guideline recommendations but provides a broader range.

Critical Safety Considerations

Concentration Awareness

• Atropine sulfate comes in different concentrations 1
• Calculate dosage carefully to avoid 10-fold errors, which are common with pediatric dosing

Administration Technique

• Administer by slow IV push for cardiac arrest to avoid paradoxical bradycardia 2
• Paradoxical bradycardia is theoretically associated with rapid administration of doses less than 0.5 mg in adults 2, though this has been disproven in pediatric patients 3

Monitoring Requirements

• Monitor heart rate and blood pressure continuously during and after administration 2
• Observe for reversal of bradycardia within 3 minutes (peak action time) 2
• Watch for tachycardia, which could worsen ischemia in patients with underlying cardiac conditions 1, 2

Common Pitfalls to Avoid

Do not routinely use atropine for RSI premedication in all pediatric patients. Despite historical recommendations, multiple studies demonstrate that atropine premedication does not prevent bradycardia in all cases and may be unnecessary for many patients. 8, 9 The practice of routine atropine administration before succinylcholine has been called into question, with some authors stating it should cease entirely. 9 However, it remains reasonable in high-risk situations. 1

Do not use atropine for type II second-degree AV block or third-degree AV block with wide-complex escape rhythm, as it is ineffective and potentially harmful in these conditions. 2

Do not withhold adequate atropine doses in organophosphate poisoning due to fear of overdose. Atropine overdose is generally well tolerated in young children 6, and inadequate dosing in true poisoning can be fatal. The therapeutic endpoint is drying of secretions and resolution of bronchospasm, not a specific dose limit. 5, 4