Atropine

General

• Type: Anticholinergic
• Routes of Administration: IV/IM/IO/SC, endotracheal, nebulized, PO, topical/ophthalmic
• Common Trade Names: Atropine, Atreza, SalTropine, AtroPen, IsoptoAtropine

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
• Ineffective in cardiac transplant patients

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

Mechanism of Action

• Parasympatholytic
  • Increases sinus/AV conduction

Indications by Condition

The following table is automatically generated from disease/condition pages across WikEM.

Indication	Dose	Context	Route	Population
Beta-blocker toxicity	0.5-1 mg IV q3-5min (max 3 mg)	Symptomatic bradycardia (initial)	IV	Adult
Calcium channel blocker toxicity	0.5-1 mg IV q2-3min (max 3 mg)	Symptomatic bradycardia	IV	Adult
Calcium channel blocker toxicity	0.02 mg/kg IV (min 0.1 mg)	Symptomatic bradycardia (pediatric)	IV	Pediatric
Carbamate poisoning	0.02-0.05mg/kg IV (min 0.1mg), double q5min until drying of secretions	Antimuscarinic, first-line	IV	Pediatric
Carbamate poisoning	1-2mg IV, double dose q5min until drying of secretions	Antimuscarinic, first-line	IV	Adult
Carbamate toxicity	0.02-0.05 mg/kg IV (min 0.1 mg), double q5min	Cholinergic toxicity antidote (muscarinic)	IV	Pediatric
Carbamate toxicity	1-2 mg IV (double q5min until atropinization)	Cholinergic toxicity antidote (muscarinic)	IV	Adult
Cholinergic crisis	2-4mg IV q5min, titrate to resolution of bronchorrhea; then infusion at 10% of loading dose/hr	Antimuscarinic, first-line	IV	Adult
Clonidine toxicity	0.5-1 mg	Bradycardia	IV	Adult
Electronic cigarettes	1-2 mg IV (double q5min until atropinization)	Cholinergic toxicity antidote (muscarinic)	IV	Adult
Electronic cigarettes	0.02-0.05 mg/kg IV (min 0.1 mg), double q5min	Cholinergic toxicity antidote (muscarinic)	IV	Pediatric
Mushroom toxicity	0.5-1mg IV (adult); 0.01mg/kg IV (peds)	Severe cholinergic symptoms (muscarinic mushrooms)	IV	Adult
Nicotine toxicity	1-2 mg IV (double q5min until atropinization)	Cholinergic toxicity antidote (muscarinic)	IV	Adult
Nicotine toxicity	0.02-0.05 mg/kg IV (min 0.1 mg), double q5min	Cholinergic toxicity antidote (muscarinic)	IV	Pediatric
Organophosphate toxicity	0.02-0.05 mg/kg (min 0.1 mg)	1st line antidote (muscarinic antagonist)	IV	Pediatric
Organophosphate toxicity	1-2 mg IV, then double q5min as needed	1st line antidote (muscarinic antagonist)	IV	Adult
Organophosphate toxicity	1-2 mg IV (double q5min until atropinization)	Cholinergic toxicity antidote (muscarinic)	IV	Adult
Organophosphate toxicity	0.02-0.05 mg/kg IV (min 0.1 mg), double q5min	Cholinergic toxicity antidote (muscarinic)	IV	Pediatric
Rapid sequence intubation	0.02 mg/kg, no minimum dose	Premedication	IV	Pediatric
Xylazine	0.5-1mg IV, may repeat q3-5min (max 3mg)	Symptomatic bradycardia	IV	Adult

See Also

• Antiarrhythmics
• Critical care quick reference
• Anticholinergic toxicity