II. Pharmacology
- Tertiary ammonium alkaloid ester of tropic acid
- Naturally occurs in plant sources
- Atropa belladonna (Deadly nightshade)
- Datura stramonium (Jimsonweed, Thorn apple)
- Described as Belladonna (beautiful woman) alkaloid
- Women of past used Atropine to dilate pupils
- Mydriasis was perceived as more attractive
- Related isomer to Scopolamine (Hyoscine)
III. Mechanism
- Antimuscarinic Cholinoceptor blocking drug
- Causes parasympathetic blockade (parasympatholytic)
- Inhibits vagal nerve activity (vagolytic)
- Enhances Sinus node automaticity
- Enhances Atrioventricular Node (AV) conduction
IV. Indications
-
Symptomatic Bradycardia associated with
- Poor perfusion
- Hypotension
- Relative Bradycardia
- Prevent vagally mediated Bradycardia with intubation
- Symptomatic Bradycardia with AV Block
-
Asystole or Pulseless Electrical Activity
- No evidence that survival is improved with Atropine
- Asystole is nearly always fatal despite intervention
- Nerve Agent Exposure
V. Dosing: Severe Bradycardia or CPR - Child
- IV Dose
- Dose: 0.02 mg/kg IV or IO every 5 minutes for up to 2 to 3 doses
- Minimum Dose: 0.1 mg
- Maximum Dose
- Child: 0.5 mg
- Teen: 1.0 mg
- Endotracheal Dose (IV/IO is preferred)
- Dose: 2-3x IV dose (0.06 mg/kg) diluted in 3-5cc NS
- Follow dose with several positive pressure breaths
VI. Dosing: Severe Bradycardia or CPR - Adult
-
Bradycardia
- Dose: 0.5-1.0 mg IV
- May repeat every 3-5 min to max total dose of 0.04 mg/kg or 3 mg
-
Asystole or Bradycardic Pulseless Electrical Activity
- Dose: 1 mg IV
- Consider giving entire 0.04 mg/kg at start)
- May repeat q3-5 min to max total dose of 0.04 mg/kg
- Endotracheal Dosing (IV/IO is preferred)
- Dose: 1-2 mg per dose
- Dilute to 10 ml with sterile water or saline
VII. Dosing: Nerve Agent Exposure
- See Nerve Agent Exposure
- Adjunct to Pralidoxime chloride (2-PAMCl)
- Atropine (Preservative-free) is indicated for muscarinic effects (bronchorrhea, bronchospasm, Bradycardia)
- Goal: Drying of secretions (will not reverse neuromuscular effects, Muscle Weakness or Respiratory Failure)
- Repeat doses until Shortness of Breath and Wheezing resolve and excess secretions reduce
- Adult
- Dose 1-2 mg slow IV push (up to 2-5 mg IV) every 15 minutes as needed
- May be given as often as every 3-5 minutes, doubling dose
- Most effective for pulmonary symptoms in adults
- Very high doses (e.g. 40 mg) may be needed
- Autoinjectors contain 2 mg Atropine
- Child <12 years
- Dose 0.015 to 0.05 mg/kg slow IV push (up to 0.1 mg/kg) every 15 minutes as needed
- May be given as often as every 3-5 minutes, doubling dose
- Most effective for CNS symptoms in children
- Pediatric autoinjectors are available
- Use 0.25 mg pen for weight <7 kg, 0.5 mg pen if 7 to 18 kg and 1 mg if 18 to 41 kg
- Use adult dose or adult autoinjector (2 mg) if weight >41 kg
- Taper dose, and discontinue by 24 hours
- Atropine may be continued as drip at 0.5 to 2.4 mg/kg/h
- Indicated for persistent symptoms (up to 48 hours may be needed in severe cases)
VIII. Precautions
- Avoid repeat dosing if possible
- Increases myocardial oxygen demand
- Atropine may provoke Ischemic Heart Disease
- Consider external pacing if repeat dosing needed
- Avoid dosing Atropine below recommended dose
- Causes paradoxical Bradycardia
- May precipitate Ventricular Fibrillation
IX. Adverse effects
- Rebound Tachycardia
- Paradoxical Bradycardia (if low dose Atropine used)
- Pupil dilatation (Mydriasis)
- Paradoxical rate slowing
- Arrhythmia (especially in Coronary Artery Disease)
- Anticholinergic Toxicity with overdosage
- Decreased Sweating and secretions
- Mild sedation to Delirium
X. Resources
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Related Studies
| atropine (on 6/21/2023 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| ATROPINE 1% EYE DROPS | Generic | $10.08 per ml |