Parenteral Manual

Physostigmine salicylate

Disclaimer: Official controlled document is the CHEO online copy. It is the responsibility of user to ensure that any paper copy version is the same as the online version before use.

Alternate Name(s): 
Original Date: 
August 2005
Revised Date: 
May 2008
  • Treatment of anticholinergic syndrome in the setting of pure anticholinergic intoxications (atropa belladonna, atropine, dimenhydrinate, diphenhydramine, jimson weed)
Reconstitution and Stability: 
  • Available as a 1 mg/mL injection
  • Stable at room temperature
  • Protect from light    

- Solutions Compatible: D5W, NS


(For approved routes of administration by nursing personnel, refer to Policy for the Administration of Intravenous Medications.)

IV Push


IV Intermittent Infusion YES
Usual dilution: undiluted
Infusion rate: do not exceed 0.5 mg/min in pediatrics, 1 mg/min in adults
IV Continuous Infusion NO

(For neonatal dosages, refer to Neonatal IV Drug Manual.)



  • 0.01-0.03 mg/kg/dose IV; may repeat after 15-20 minutes to a maximum total dose of 2 mg


  • 0.5-2 mg IV/IM initially, may repeat Q 20 minutes.  May be necessary to use additional doses of 1-4 mg given Q 30-60 minutes as life-threatening signs (arrhythmias, seizures) recur.
Potential hazards of parenteral administration: 
  • Overdosage can cause cholinergic crisis (symptoms include:  salivation, sweating, emesis, miosis, urination, diarrhea, confusion, coma, muscle weakness, paralysis)
  • Antidote:  mechanical ventilation and atropine               
  • Atropine must be available to reverse excess cholinergic side effects (give 0.5 mg of atropine for every mg of physostigmine)   
  • Contraindicated in patients with asthma, gangrene, diabetes, cardiovascular diseases, intestinal or urogenital obstruction and patients receiving choline esters or depolarizing muscular blocking agents
  • No longer recommended for drug overdose/acute toxicity of medications that possess dose-related anticholinergic properties (ie: tricyclic antidepressants, intrathecal baclofen)
  • Caution in patients with epilepsy or bradycardia
  • Onset:  3-8 minutes
  • Duration:  30 minutes - 5 hours
  • Monitor heart rate and respiratory rate
  • Contains benzyl alcohol and sodium bisulphite
  • Readily penetrates the blood brain barrier

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