Neostigmine Metilsulfate

Note: Neostigmine (Prostigmin) tablets have been discontinued in the US for more than 1 year. Myasthenia gravis: Diagnosis: Canadian labeling: Note: Pretreatment with atropine is recommended, and atropine should be available if a cholinergic reaction occurs. IM: 0.022 mg/kg as a single dose. If test is inconclusive, retesting can be done on a different day with a single dose of 0.031 mg/kg. Myasthenia gravis: Treatment: Canadian labeling: Oral: Initial dose: 15 mg 3 times daily. Usual dose: 150 mg in divided doses, administered over a 24-hour period; interval between doses should be adjusted per patient response with larger doses provided at times of most fatigue. Dosage range: 15 to 375 mg daily in divided doses. IM, IV, SubQ: 0.5 to 2.5 mg; dosing based on individual patient response Reversal of nondepolarizing neuromuscular blockade after surgery: US labeling: Bloxiverz: IV: Note: An anticholinergic agent (atropine or glycopyrrolate) should be given intravenously prior to or in conjunction with neostigmine; in the presence of bradycardia, administer the anticholinergic prior to neostigmine. Peripheral nerve stimulation delivering train-of-four (TOF) stimulus must also be used to determine time of neostigmine initiation and need for additional doses. Prior to administration, there must be a twitch response to the first stimulus in the TOF of at least 10% of baseline. Usual dose: 0.03 to 0.07 mg/kg generally achieves a TOF twitch ratio of 90% within 10 to 20 minutes of administration; maximum total dose: 0.07 mg/kg or 5 mg (whichever is less) Dose selection guide: The 0.03 mg/kg dose is recommended for reversal of NMBAs with shorter half-lives (eg, rocuronium); or when the first twitch response to the TOF stimulus is substantially >10% of baseline or when a second twitch is present. The 0.07 mg/kg dose is recommended for NMBAs with longer half-lives (eg, vecuronium, pancuronium); or when the first twitch response is relatively weak (ie, not substantially >10% of baseline); or rapid recovery is needed. Canadian labeling: IV: 0.5 to 2.5 mg; repeat as required. Only in exceptional cases should the total dose exceed 5 mg. Note: Administer with atropine 0.6 to 1.2 mg intravenously in a separate syringe several minutes before neostigmine. Postoperative bladder distention/urinary retention: IM, SubQ: Canadian labeling: Prevention: 0.25 mg as soon as possible after operation; repeat every 4 to 6 hours for 2 to 3 days. Treatment: 0.5 to 1 mg; if urination does not occur within an hour, patient should be catheterized. After the bladder has emptied or patient has voided, doses may be repeated every 3 hours for 5 doses. Acute colonic pseudo-obstruction (Ogilvie syndrome) (off-label use): IV: 2 mg over 3 to 5 minutes (Ponec 1999). Note: Administration over 60 minutes may reduce the incidence of bradycardia; however, efficacy may be reduced (Abeyta 2001). Ensure atropine is available at the bedside to treat symptomatic neostigmine-induced bradycardia.