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
  • reduces salivation and excessive secretions of the respiratory tract
  • IV Direct:
    • 0.5-1mg q3-5min until desired rate achieved
  • IM/SC:
    • 0.4-0.6mg q4-6h prn 
  • 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:
  • ECG
  • HR
CCTC Protocol:
  • May be administered IV direct by an approved nurse in the CCTC.
  • May be administered as 0.5mg IV direct without a physician's order by a certified nurse in the CCTC for symptomatic bradycardia <50beats/min (i.e. hypotension, decreased level of consciousness, ventricular ectopics or myocardial ischemia/pain).


Lynne Kelly, Pharmacist, CCTC
Brenda Morgan, Clinical Nurse Specialist, CCTC
Last Update: August 7, 2006

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Last Updated March 24, 2009 | © 2007, LHSC, London Ontario Canada