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Pyridostigmine Side Effects

Medically reviewed by Last updated on May 8, 2024.

Applies to pyridostigmine: oral conventional 30-mg tablets for military use, oral conventional 60-mg tablets and extended-release tablets, oral oral solution, parenteral injection.


    Military Use for Soman Poisoning Prophylaxis
  • Use of pyridostigmine alone is not protective against soman effects.111 Efficacy depends on rapid use of nerve agent antidotes (i.e., atropine and pralidoxime) following nerve agent exposure.111

  • Protective garments (e.g., masks, hoods, overgarments) specifically designed for protection from chemical nerve agents are the primary means of protection against nerve agent exposure; do not rely solely on pretreatment with pyridostigmine, atropine, and pralidoxime to provide complete protection.111

  • Do not administer pyridostigmine after soman exposure.111 Discontinue at first sign of nerve agent poisoning; may exacerbate effects of a sublethal exposure.111

    Experience of Health Care Personnel
  • Pyridostigmine should be administered by IV injection only by adequately trained individuals familiar with the drug’s actions, characteristics, and risks.124

Side effects include:

Diarrhea, abdominal pain or cramps, dysmenorrhea, increased flatus, nausea, urinary urgency and frequency.

For Healthcare Professionals

Applies to pyridostigmine: injectable solution, oral syrup, oral tablet, oral tablet extended release.


Frequency not reported: Nausea, vomiting, diarrhea, abdominal cramps, GI hypermotility, salivary hypersecretion[Ref]


Frequency not reported: Increased bronchial secretion combined with bronchoconstriction[Ref]


Frequency not reported: Muscle weakness, fasciculation, tremors, muscle cramps, muscle hypotonia[Ref]


Frequency not reported: Miosis, increased lacrimation, accommodation disorders[Ref]


Frequency not reported: Rash, hyperhidrosis[Ref]


Frequency not reported: Arrhythmia (including bradycardia, tachycardia, AV block), syncope, hypotension[Ref]


Frequency not reported: Urinary urgency[Ref]

Frequently asked questions


1. (2001) "Product Information. Mestinon (pyridostigmine)." ICN Pharmaceuticals Inc

2. (2002) "Product Information. Regonol (pyridostigmine)." Organon

3. Cerner Multum, Inc. "UK Summary of Product Characteristics."

4. Cerner Multum, Inc. "Australian Product Information."

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.