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Pyridostigmine Dosage

Medically reviewed on November 20, 2017.

Applies to the following strengths: 5 mg/mL; 180 mg; 60 mg; 60 mg/5 mL

Usual Adult Dose for Nerve Agent Pretreatment

Soman pretreatment:
30 mg orally every 8 hours starting at least 8 hours before anticipated nerve gas exposure.

Pyridostigmine is not effective and should not be taken at the time of, or after exposure to, nerve agents. Immediate treatment with parenteral atropine and pralidoxime is required if nerve agent exposure occurs.

Pretreatment has been used for up to 14 to 21 days.

Pyridostigmine has also been used as nerve agent pretreatment (NAPP) against other substances. In animal studies, pretreatment, together with atropine and pralidoxime postexposure treatment, was effective in increasing survival after tabun and soman poisoning, variably effective against cyclosarin, and ineffective against sarin and VX.

Usual Adult Dose for Reversal of Nondepolarizing Muscle Relaxants

10 to 20 mg by slow IV injection.
Atropine sulfate 0.6 to 1.2 mg IV is recommended immediately before pyridostigmine injection.

Airway and ventilation should be maintained until recovery of normal respiration.

Usual Adult Dose for Myasthenia Gravis

Immediate-release tablets and syrup:
Initial dose: 60 mg orally 3 times daily.
Maintenance dose: Increase dose as needed in intervals of at least 48 hours. Results of dose adjustments may take several days to become apparent. Effective doses have range from 60 mg to 1500 mg per day in 3 to 6 divided doses.

Sustained-release tablets: 180 to 540 mg orally once or twice daily, not more often than 6-hour intervals. May be used with immediate-release tablets or syrup to provide accurate dose titration and optimal control of symptoms.

2 to 5 mg IM or slow IV every 2 to 3 hours. To supplement oral dosage pre- and postoperatively, during labor and postpartum, during myasthenic crisis (differentiate between cholinergic and myasthenic crisis before administering), or when oral therapy is not possible, one-thirtieth of the oral dose (i.e., 2 mg IV for every 60 mg oral) may be given.

The use of continuous IV infusions at rates of 2 to 4 mg/hour has been reported in the management of myasthenic crisis.

Usual Pediatric Dose for Reversal of Nondepolarizing Muscle Relaxants

Children: 0.1 to 0.25 mg/kg/dose IV preceded by atropine or glycopyrrolate

Airway and ventilation should be maintained until recovery of normal respiration.

Usual Pediatric Dose for Myasthenia Gravis

Myasthenia gravis: Dosage should be adjusted such that larger doses administered prior to time of greatest fatigue.

Neonatal: (A benzyl alcohol-free formulation should be used for neonates):
Oral: 5 mg every 4 to 6 hours
IM, IV: 0.05 to 0.15 mg/kg/dose

Oral: 7 mg/kg/day in 5 to 6 divided doses
IM, IV: 0.05 to 0.15 mg/kg/dose (maximum single dose: 10 mg)

Renal Dose Adjustments

Dose adjustments may be required in patients with renal insufficiency. The dose should be individually titrated to achieve optimum response.

Liver Dose Adjustments

Data not available


Pyridostigmine is contraindicated for use in patients with mechanical intestinal or urinary obstruction.

Extreme caution should be used in patients with bronchial asthma or cardiac arrhythmias.

Although failure of patients to show clinical improvement may be indicative of underdosage, it can also be reflective of overdosage. As is true of all cholinergic drugs, overdosage may result in cholinergic crisis characterized by increasing muscle weakness leading to potentially fatal respiratory arrest. Myasthenic crisis due to an increase in the severity of the disorder is also accompanied by extreme muscle weakness, and thus may be difficult to distinguish from cholinergic crisis on a symptomatic basis. Such differentiation is extremely important, since increases in dosage of pyridostigmine or other drugs of this class in the presence of cholinergic crisis or of a refractory or "insensitive" state could have grave consequences. Osserman and Genkins indicate that the differential diagnosis of the two types of crisis may require the use of edrophonium as well as clinical judgment. The treatment of the two conditions obviously differs substantially. Whereas the presence of myasthenic crisis suggests the need for more intensive anticholinesterase treatment, the diagnosis of cholinergic crisis, according to Osserman and Genkins, calls for the prompt withdrawal of all drugs of this type. The immediate use of atropine in cholinergic crisis is also advised.

Atropine may also be used to abolish or obtund gastrointestinal reactions or other muscarinic side effects; but such use, by masking signs of overdosage, can lead to inadvertent induction of cholinergic crisis.

If used as an antagonist to nondepolarizing muscle relaxants, patients should be closely monitored and respiratory assistance not discontinued until voluntary respiration has adequately recovered.

Dose adjustments may be required in patients with renal impairment.

Pyridostigmine is not effective and should not be taken at the time of, or after exposure to, nerve gas. Immediate treatment with atropine and pralidoxime is required.

Some formulations of pyridostigmine injection contain benzyl alcohol which should not be used in neonates.


Data not available on the dialysis clearance of pyridostigmine; however, dose adjustments may be required in patients with renal insufficiency.

Further information

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