pyridostigmine

Generic Name: pyridostigmine (py rid o STIG meen)

Brand names: Mestinon, Mestinon Timespan, Regonol

What is pyridostigmine?

Pyridostigmine affects chemicals in the body that are involved in the communication between nerve impulses and muscle movement.

Pyridostigmine is used to treat the symptoms of myasthenia gravis. It is also used in military personnel who have been exposed to nerve gas.

Pyridostigmine may also be used for purposes not listed in this medication guide.

What is the most important information I should know about pyridostigmine?

You should not use pyridostigmine if you are allergic to it, or if you have a bladder or bowel obstruction.

Before taking pyridostigmine, tell your doctor if you have asthma, kidney disease, an ulcer or other serious stomach disorder, high blood pressure, heart disease, overactive thyroid, or a history of seizures.

The amount and timing of this medicine is extremely important to the success of your treatment. Carefully follow your doctor's instructions about how much medicine to take and when to take it.

This medication may cause blurred vision or impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.

Your doctor may occasionally change your dose to make sure you get the best results. You may be asked to keep a daily record of when you took each dose and how long the effects lasted. This will help your doctor determine if your dose needs to be adjusted.

If you need surgery, tell the surgeon ahead of time that you are using pyridostigmine. You may need to stop using the medicine for a short time.

What should I discuss with my health care provider before taking pyridostigmine?

You should not use pyridostigmine if you are allergic to it, or if you have a bladder or bowel obstruction.

To make sure you can safely take pyridostigmine, tell your doctor if you have any of these other conditions:

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  asthma;

  
  


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  kidney disease;

  
  


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  an ulcer or other serious stomach disorder;

  
  


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  high blood pressure, heart disease;

  
  


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  overactive thyroid; or

  
  


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  a history of seizures.

  
  

It is not known whether pyridostigmine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication. It is not known whether pyridostigmine passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take pyridostigmine?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Take this medicine with food or milk if it upsets your stomach. Do not crush, chew, or break an extended-release tablet. Swallow it whole. Breaking or opening the pill may cause too much of the drug to be released at one time.

Measure liquid medicine with a special dose measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose measuring device, ask your pharmacist for one.

The amount and timing of this medicine is extremely important to the success of your treatment. Carefully follow your doctor's instructions about how much medicine to take and when to take it.

Your doctor may occasionally change your dose to make sure you get the best results. You may be asked to keep a daily record of when you took each dose and how long the effects lasted. This will help your doctor determine if your dose needs to be adjusted.

If you need surgery, tell the surgeon ahead of time that you are using pyridostigmine. You may need to stop using the medicine for a short time. Store at room temperature away from moisture and heat.

Keep the tablets in their original container, along with the canister of moisture-absorbing preservative that comes with this medicine.

See also: Pyridostigmine dosage (in more detail)

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include nausea, vomiting, diarrhea, stomach cramps, sweating, blurred vision, drooling, and weak or shallow breathing.

Worsening muscle weakness, or no change in your myasthenia gravis symptoms, may also be signs of overdose.

What should I avoid while taking pyridostigmine?

This medication may cause blurred vision or impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly. Drinking alcohol can increase certain side effects of pyridostigmine.

Pyridostigmine side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using pyridostigmine and call your doctor at once if you have any of these serious side effects:

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  extreme muscle weakness, muscle twicthing;

  
  


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  slurred speech, vision problems;

  
  


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  severe vomiting or diarrhea;

  
  


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  cough with mucus;

  
  


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  confusion, anxiety, panic attacks;

  
  


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  seizure (convulsions); or

  
  


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  worsening or no improvement in your symptoms of myasthenia gravis.

  
  

Less serious side effects may include:

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  cold sweat, pale skin;

  
  


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  urinating more than usual;

  
  


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  watery eyes;

  
  


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  mild nausea, vomiting, or upset stomach;

  
  


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  warmth or tingly feeling; or

  
  


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  mild rash or itching.

  
  

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Pyridostigmine Dosing Information

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:

Oral:
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.

Parenteral:
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

Children:
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)

What other drugs will affect pyridostigmine?

Tell your doctor about all other medicines you use, especially:

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  atropine (Atreza, Sal-Tropine);

  
  


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  belladonna (Donnatal, and others);

  
  


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  benztropine (Cogentin);

  
  


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  clidinium (Quarzan);

  
  


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  clozapine (Clozaril, FazaClo);

  
  


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  dimenhydrinate (Dramamine);

  
  


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  methscopolamine (Pamine), scopolamine (Transderm Scop);

  
  


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  glycopyrrolate (Robinul);

  
  


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  mepenzolate (Cantil);

  
  


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  bladder or urinary medications such as darifenacin (Enablex), flavoxate (Urispas), oxybutynin (Ditropan, Oxytrol), tolterodine (Detrol), or solifenacin (Vesicare);

  
  


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  bronchodilators such as ipratropium (Atrovent) or tiotropium (Spiriva);

  
  


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  cold medicine, allergy medicine, or sleeping pills that contain an antihistamine such as diphenhydramine (Tylenol PM) or doxylamine (Unisom);

  
  


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  heart rhythm medication such as quinidine (Quin-G), procainamide (Procan, Pronestyl), disopyramide (Norpace), flecaininde (Tambocor), mexiletine (Mexitil), propafenone, (Rythmol), and others;

  
  


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  irritable bowel medications such as dicyclomine (Bentyl), hyoscyamine (Hyomax), or propantheline (Pro Banthine);

  
  


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  medicine to treat Alzheimer's dementia, such as donepezil (Aricept), rivastigmine (Exelon), or tacrine (Cognex); or

  
  


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  a steroid such as betamethasone (Celestone) or dexamethasone (Cortastat, Dexasone, Solurex, DexPak).

  
  

This list is not complete and other drugs may interact with pyridostigmine. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

More pyridostigmine resources

• Pyridostigmine Side Effects (in more detail)
• Pyridostigmine Dosage
• Pyridostigmine Use in Pregnancy & Breastfeeding
• Drug Images
• Pyridostigmine Drug Interactions
• Pyridostigmine Support Group
• 12 Reviews for Pyridostigmine - Add your own review/rating

• Pyridostigmine Prescribing Information (FDA)


• Pyridostigmine MedFacts Consumer Leaflet (Wolters Kluwer)


• Mestinon Prescribing Information (FDA)


• Pyridostigmine Bromide Monograph (AHFS DI)


• Regonol Prescribing Information (FDA)

Compare pyridostigmine with other medications

• Dysautonomia
• Myasthenia Gravis
• Nerve Agent Pretreatment
• Reversal of Nondepolarizing Muscle Relaxants

Where can I get more information?

• Your pharmacist can provide more information about pyridostigmine.

See also: pyridostigmine side effects (in more detail)