Parenteral Manual

Neostigmine methylsulfate

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): 
Antidote, cholinergic agent, diagnostic agent
Original Date: 
August 2005
Revised Date: 
May 2009
  • Treatment of supraventricular tacycardia
  • Treatment of myasthenia gravis
  • Prevent and treat postoperative bladder distention and urinary retention
  • Reversal of the effects of nondepolarizing neuromuscular blocking agents after surgery
Reconstitution and Stability: 
  • Available as 0.5 mg/mL ampoules
  • Protect from light and freezing
  • Keep at room temperature

- Solutions Compatible: dextrose up to D10W, 0.9% NaCl, dextrose-saline combinations, ringer's solution, ringer's lactate

- Additive/Above Cassette Compatible: glycopyrrolate, pentobarbital, thiopental

- Y-site Compatible: heparin, KCl (40 mmol/L)

- Incompatible: no information


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

IV Push

Usual dilution: undiluted
Infusion time: slowly over several minutes
Infusion rate: do not exceed 0.5 mg/minute

IV Intermittent Infusion


IV Continuous Infusion NO




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


-Supraventricular tachycardia:

  • 0.01 - 0.04 mg/kg/dose IV
  • Maximum: 2.5 mg/dose

- Myasthenia gravis:    

  • Diagnosis: 0.025-0.04 mg/kg IM as a single dose
  • Treatment: 0.01-0.04 mg/kg IM/IV/SC Q2-4H
  • Maximum: 2.5 mg/dose

- Reversal of nondepolarizing neuromuscular blockage:

  • Infants: 0.025-0.1 mg/kg/dose IV
  • Children: 0.025-0.08 mg/kg/dose IV


- Myasthenia gravis:

  • Diagnosis: 0.02 mg/kg IM as a single dose
  • Treatment: 0.5-2.5 mg IM/IV/SC Q 1-3 hours
  • Maximum: 10 mg/24 hours

- Reversal of nondepolarizing neuromuscular blockage:

  • 0.5-2.5 mg IV repeat PRN
  • Maximum: 5 mg total dose

- Bladder atony:   

  • Prevention: 0.25 mg IM/SC Q4-6H for 2-3 days
  • Treatment: 0.5-1 mg IM/SC Q3H for 5 doses after bladder has emptied


  • CrCl 10-50 mL/min:  Administer 50% of normal dose
  • CrCl <10 mL/min:  Administer 25% of normal dose
Potential hazards of parenteral administration: 
  • Hypotension
  • Respiratory distress (Antidote: atropine and artificial ventilation)
  • Cholinergic effects: nausea, vomiting, diarrhea, salivation, dizziness, bradycardia
  • Tremor, weakness, muscle cramping
  • Thrombophlebitis
  • Incontinence



  • To counteract the adverse cholinergic effects, administer with an anticholinergic agent (ie. atropine, glycopyrrolate)
  • For diagnosis of myasthenia gravis, all cholinesterase medications should be discontinued at least 8 hours before neostigmine and atropine should be administered IV immediately prior to or IM 30 minutes before neostigmine
  • Monitor muscle strength, heart rate, respiratory rate
  • Onset: 1-20 minutes (IV), 20-30 minutes (IM)
  • Duration: 1-2 hours (IV), 2-4 hours (IM)
  • Have atropine and epinephrine on hand for any hypersensitivity reactions
  • Does not antagonize and may prolong the phase I block of depolarizing muscle relaxants (eg: succinylcholine).

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