Atropine
Classification
Anticholinergic
Antimuscarinic
Indications
ACP: Restoration of heart rate in bradydysrhythmias
ACP: Sinus bradycardia (rate < 50/minute) with hemodynamic compromise
ACP: Bradycardia secondary to atrioventricular nodal blocks
ACP: Treatment of organophosphate poisoning
ACP: Control of secretions in palliative care (requires additional endorsement)
Contraindications
- Hypersensitive to atropine or other anticholinergics
- Tachycardia
- Narrow-angle glaucoma
- Thyrotoxicosis
- Prostatic hypertrophy
- Myasthenia gravis
Adult dosages
Atropine must be given in the correct dose and must be given quickly: underdosing, or slow administration, may cause paradoxical slowing of the heart rate
ACP: Bradycardia
- 0.6 mg IV push to maximum dose of 0.04 mg/kg (~3 mg in most patients)
- CliniCall consultation required prior to administration to discuss treatment plan.
- 1-2 mg IM/IV; repeat every 5-60 minutes until symptoms resolve
ACP: Secretion control in palliative care
- 0.6 mg IM
Pediatric Considerations And Dosing
Atropine must be given in the correct dose and must be given quickly: underdosing, or slow administration, may cause paradoxical slowing of the heart rate
ACP: Bradycardia
- 0.02 mg/kg IV push; minimum dose 0.1 mg; maximum dose 0.04 mg/kg
- CliniCall consultation required prior to administration to discuss treatment plan.
- 0.02-0.05 mg/kg IV; repeat every 10-20 minutes until symptoms resolve
How Supplied
Ampoule: 0.6 mg/mL (1 mL ampoule)
Mechanism Of Action
Atropine competitively antagonizes acetylcholine at muscarinic receptors, producing parasympatholytic and vagolytic effects.
Pharmacokinetics
- Onset: < 2 minutes (IM/IV)
- Peak: 3 minutes (IM); 2-4 minutes (IV)
- Duration: 2-6 hours(IM/IV)
Adverse Effects
Common adverse effects include tachycardia, dry mouth, headaches, blurred vision, and dysphagia.
Overdose
Signs and symptoms of overdose are similar to adverse effects.
Warning And Precautions
Atropine produces pupillary dilation. Assessment of pupils may be unreliable.
Some evidence exists that suggests atropine may be heat sensitive, losing some potency after 4+ weeks of storage at temperatures consistently above 40°C. Degraded medication is unlikely to be harmful to patients, but may not carry the same clinical effects, thus requiring higher doses.