Classification: anticholingergic
  • used in the treatment of symptomatic sinus bradycardia (not recommended for bradycardias below AV  node such as Type II 2o, or complete AV block)
  • antidote for sinus bradycardia induced by drugs or toxic substances or neurological disorders (which may be induced by suctioning)
  • reduces salivation and excessive secretions of the respiratory tract
Dose: IV Direct:
  • 0.5-1mg q3-5min until desired rate achieved


  • 0.4-0.6mg q4-6h prn 


  • 2-3 mg prefilled syringe
  • when used as a cholinergic antidote may require larger frequent doses
  • slow IV administration may result in paradoxical bradycardia and is not recommended
  • may be given via endotracheal tube if IV administration not possible
Adverse Effects:
  • tachycardia
  • respiratory depression
  • blurred vision
  • dilated pupils
  • dry mouth
  • flushed dry skin
  • ileus
  • urinary retention
  • in myasthenia gravis, glaucoma, paralytic ileus, urinary obstruction
Drug Interactions:
  • atropine + phenothiazines = increased anticholinergic effect
  • atropine + quinidine = increased anticholinergic effect
  • atropine + procainamide = increased anticholinergic effect
Monitoring Therapy:
  • continuous heart rate and rhythm
  • blood pressure
Adult Critical Care Protocol:
  • May be administered IV direct by an approved nurse in the CCTC.
  • May be administered as 0.5mg IV direct my medical directive by a certified nurse or RRT in Adult Critical Care for symptomatic bradycardia <60 beats/min and at least one sign or symptom (i.e. hypotension, decreased level of consciousness, signs of shock or myocardial ischemia/pain).

    A certified nurse or RRT may administer additional doses of 1 mg every 3 minutes to a maximum total dose of 3 mg.


Lynne Kelly, Pharmacist, CCTC
Brenda Morgan, Clinical Nurse Specialist, CCTC
Last Update: September 19, 2018