Atropine

General

• Type: Anticholinergic
• Dosage Forms: IV/IM/IO/SC, endotracheal, nebulized, PO, topical/opthalmic
• Common Trade Names:

Adult Dosing

• Symptomatic bradyarrhythmia or AV block, : 0.5 mg IV rapid push q3-5m (max = 0.04 milligram/kg)
• Cardiac arrest (bradyasystolic): 1mg IV/IM/subQ/endotracheally q3-5m
• Organophosphate toxicity: 1-3mg IV/IM/SC/endotracheally q10-30m, max 3 doses
• IBS, PUD: 0.4-0.6 mg PO or IV/IM/SC q4-6h
• Cycloplegia/mydriasis induction: 1-2 drops of 1% solution 1-3 times daily

Pediatric dosing

• Symptomatic bradyarrhythmia or AV block: 0.01-0.03 mg/kg IV/IO q1-2h
• Cardiac arrest (bradyasystolic): 0.01-0.03 mg/kg IV/IM/subQ/endotracheally
• Organophosphate toxicity: 0.01-0.03 mg/kg IV/IM/subQ/endotracheally
• IBS, PUD: 0.01 mg/kg (max 0.4 mg or 0.3 mg/m2) PO/SC q4-6h
• Cycloplegia/mydriasis induction: 1-2 drops of 1% solution 1-3 times daily

Special Populations

• Pregnancy Rating: C
• Lactation: Infant risk cannot be ruled out
• Renal Dosing: no adjustment
• Hepatic Dosing: no adjustment

Contraindications

• Allergy to class/drug
• Primary glaucoma or predisposition to narrow anterior chamber angle glaucoma

Adverse Reactions

Serious

• Cardiac dysrhythmia, tachyarrhythmia
• If given slowly or in amounts <0.5mg, may cause paradoxical bradycardia
• Increased O2 consumption
• Hypotension
• Coma
• Respiratory depression
• Glaucoma

Common

• Constipation, xerostomia
• Blurred vision, decreased lacrimation, eye pain, photophobia, superficial keratitis

Pharmacology

• Half-life:
• Metabolism: hepatic
• Excretion: renal
• Onset of action (IV) = 2-4min
• Duration of action (IV) = 5hr

Mechanism of Action

• Parasympatholytic
  • Increases sinus/AV conduction

See Also

• Antiarrhythmics
• Critical care quick reference
• Anticholinergic toxicity