• Cholinergic (anticholinesterase inhibitor)

Pyridostigmine (peer-id-oh-STIG-meen) is taken by mouth for protection against a nerve agent called soman. It should be used along with wearing protective clothing including a gas mask, hood and overgarment.

It is very important that pyridostigmine use be stopped at the first sign of nerve agent poisoning. Atropine and pralidoxime [2-PAM] are medicines that must be taken at the first sign of nerve agent poisoning and immediately after pyridostigmine use has stopped. Atropine and 2-PAM are called antidotes and help the pyridostigmine work better against nerve agent poisoning.

Pyridostigmine is to be administered to military personnel only by or under the immediate supervision of your chain of command or medical officer. It is available in the following dosage form:

Oral
• Tablet (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your medical officer will make. For pyridostigmine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to pyridostigmine or any of the anticholinesterase agents (certain drugs used during surgery like physostigmine, edrophonium, neostigmine, and ambenonium). Also tell your medical officer if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Pyridostigmine has not been studied in pregnant women. However, pyridostigmine has not been shown to cause birth defects or other major problems in animal studies.

Breast-feeding—It is not known if pyridostigmine passes into breast milk.

Older adults—May medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of pyridostigmine in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

• Asthma (in the bronchial tubes) or
• Irregular or slowed heartbeat or
• Slowed rate of breathing—Pyridostigmine may make the condition worse

• Bladder blockage or
• Bowel blockage—Pyridostigmine should not be used if you have these medical problems

• Bromide allergy—Rash and other side effects may occur

Dosing—

Take this medicine exactly as directed. Do not skip, double up on your dose, or stop taking it unless directed by your medical officer. Taking pyridostigmine right before being exposed to soman nerve agent (e.g., when the gas attack alarm is given) or at the same time as poisoning by soman may not work. And, it may make the symptoms of an exposure to soman much worse.

Pyridostigmine use must be stopped at the first sign of nerve agent poisoning. Tell your medical officer or chain of command if you think you may have symptoms of nerve agent poisoning such as weak muscles or trouble breathing.

It is important that you wear protective clothes such as masks, hoods and overgarments designed to protect against nerve agent poisoning.

The dose of pyridostigmine will be determined by your chain of command and/or medical officer based on the threat of soman nerve agent exposure. Follow your medical officer's directions about how much and when to take this medicine.. The following is the dosing information for pyridostigmine.

• For oral dosage form (tablets):
  • For protection against soman nerve agent poisoning:
    • Adults—The usual dose is one 30 mg tablet every 8 hours

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Store in the refrigerator.
• Store away from direct light.
• Do not keep outdated medicine or medicine no longer needed. Ask your medical officer how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.

If you experience serious side effects such as difficulty breathing, severe dizziness, or loss of consciousness after taking pyridostigmine, you should contact your medical officer immediately.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

• Incidence not determined
  • blue lips and fingernails;  chest pain ;  cough producing mucus or sometimes producing a pink frothy sputum;  difficult, fast, noisy breathing, sometimes with wheezing;  inability to breath without assistance;  increased sweating;  irregular heartbeat;  loss of bladder control;  loss of bowel control;  loss of consciousness ;  mood or mental changes;  no blood pressure or pulse;  numbness, tingling, pain, or weakness in hands or feet;  pale skin;  paleness of skin after fainting;  seizures ;  stiffness of upper body and arms;  stopping of heart;  swelling in legs and ankles;  trembling;  unconsciousness;  weakness after fainting;  weakness and heaviness of legs 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Cramps;  diarrhea;  pain;  heavy bleeding;  stomach pain 
  
  

• Less common
  • Bloody nose;  burning feeling;  change in vision;  crawling, itching feeling;  difficulty in moving;  dry skin;  impaired vision;  increased need to urinate;  joint pain;  muscle aching or cramping;  muscle pains or stiffness;  neck pain;  numbness;  passing urine more often;  “pins and needles” feeling;  prickling feeling;  swollen joints;  tingling feeling 
  
  

• Incidence not determined
  • Anxiety;  bloated, full feeling;  discouragement;  dizziness;  dry mouth;  excess air or gas in stomach or intestines;  excessive muscle tone;  eye pain;  feeling of constant movement of self or surroundings;  feeling of sluggishness ;  feeling sad or empty;  hair loss;  headache;  hyperventilation ;  irritability;  lack of appetite;  lightheadedness;  loss of interest or pleasure;  mental problems;  muscle tension or tightness;  nausea ;  nervousness;  no blood pressure or pulse;  numbness of the tongue;  passing gas;  rash;  restlessness;  seeing things that are not there;  seizures;  sensation of spinning;  shaking;  stiffness of upper body and arms;  swelling;  thinning of hair;  tingling of extremities;  trouble concentrating;  trouble sleeping;  unusual dullness;  vomiting;  warm sensation;  wheezing 
  
  

• Symptoms of overdose

  Get emergency help immediately if any of the following symptoms of overdose occur

  • blurred vision;  diarrhea;  frequent urge to urinate;  increasing muscle weakness or paralysis, especially in the arms, neck, shoulders, and tongue;  muscle cramps or twitching;  nausea;  shortness of breath;  slow heartbeat;  small pupils;  stomach cramps or pain;  sweating;  tightness in chest;  unusual tiredness or weakness;  vomiting;  watering of eyes or mouth;  wheezing 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.