In the U.S.—

In Canada—

Other commonly used names are 2-PAM; 2-PAM chloride.

• Antidote, to cholinesterase inhibitors
• Antidote, to organophosphate chemicals
• Antidote, to organophosphate pesticides

Pralidoxime ( pra-li-DOX-eem) is used together with another medicine called atropine to treat poisoning caused by organic phosphorus pesticides (e.g., diazinon, malathion, mevinphos, parathion, and sarin) and by organophosphate chemicals (“nerve gases”) used in chemical warfare. Pralidoxime is also used to treat overdose of medicines, such as ambenonium, neostigmine, and pyridostigmine, that are used to treat myasthenia gravis. Poisoning with these chemicals or medicines causes your muscles, including the muscles that help you breathe, to become weak. Pralidoxime is used to help you get back strength in your muscles.

Pralidoxime is to be given only by or under the direct supervision of a doctor or trained military personnel. It is available in the following dosage form:

Parenteral
• Injection (U.S. and Canada)

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 doctor will make. For pralidoxime, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to pralidoxime. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Studies on effects in pregnancy have not been done in either humans or animals.

Breast-feeding—It is not known whether pralidoxime passes into breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.

Children—Although there is no specific information comparing use of pralidoxime in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in adults.

Older adults—Many 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 information comparing use of pralidoxime 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. When you are using pralidoxime, it is especially important that your health care professional know if you are taking any of the following:

• Aminophylline (e.g., Somophyllin) or
• Caffeine (e.g., NoDoz) or
• Theophylline (e.g., Theo-Dur, Somophyllin-T)—These medicines may make the effects of the poisoning worse

• Kidney disease—The effects of this medicine may be increased

• Myasthenia gravis—This medicine may make the condition worse

For patients using the pralidoxime auto-injector (automatic injection device):

• You will be trained to use the pralidoxime auto-injector by a medic or other trained military personnel. You will also be told the conditions under which it should be used. The auto-injector also comes with patient directions. Read them carefully before you actually need to use this medicine. Then, when an emergency arises, you will know how to inject the pralidoxime.
• It is important that you do not remove the safety cap on the auto-injector until you are ready to use it. This prevents spillage of the medicine from the device during storage and handling.
• To use the pralidoxime auto-injector:
  • Remove the gray safety cap.
  • Place the black tip of the device on the thigh, with the injector pointed straight at the thigh.
  • Press hard into the thigh until the auto-injector functions. Hold in place for several seconds. Remove the auto-injector and dispose of it as directed.
  • Massage the injected area for 10 seconds.

Use this medicine only as directed. Do not use more of it and do not use it more often than your doctor or medic ordered. Do not use more than recommended on the label unless otherwise directed by your doctor or medic.

Dosing—

The dose of pralidoxime will be different for different patients. Follow your doctor's or medic's orders or the directions on the label. The following information includes only the average doses of pralidoxime.

• For injection dosage form:
  • For treatment of organic phosphorus pesticide poisoning:
    • Adults and teenagers—The usual dose is 1 to 2 grams injected into a vein. The dose may be repeated after one hour, and then every eight to twelve hours if muscle weakness continues.
    • Children—The dose is based on body weight and must be determined by your doctor. It is usually 25 to 50 milligrams (mg) per kilogram (kg) (11.35 to 22.7 mg per pound) of body weight injected into a vein. The dose may be repeated after one hour, and then every eight to twelve hours if muscle weakness continues.
  • For treatment of organic phosphorus chemical (“nerve gas”) poisoning:
    • Adults—The usual dose is 600 mg injected into a muscle. The dose may be repeated fifteen minutes after the first dose and again fifteen minutes after the second dose, if needed.
    • Children—Dose must be determined by your doctor.
  • For treatment of overdose of medicines used to treat myasthenia gravis:
    • Adults and teenagers—At first, the dose is 1 to 2 grams injected into a vein. Then, the dose is 250 mg injected into a vein every five minutes.
    • Children—Dose must be determined by your doctor.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Keep the medicine from freezing. Do not refrigerate.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

This medicine will add to the effects of CNS depressants (medicines that may make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.

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 as soon as possible if any of the following side effects occur:

• More common
  • Blurred or double vision;  difficulty in focusing your eyes;  difficulty in speaking;  difficult or rapid breathing;  dizziness ;  fast heartbeat;  muscle stiffness or weakness;  pain at the place of injection (after injection into a muscle) 
  
  

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
  • Drowsiness;  headache;  nausea 
  
  

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

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although this use is not included in product labeling, pralidoxime has been used in some patients to treat poisoning caused by certain carbamate pesticides.

Other than the above information, there is no additional information relating to proper use, precautions, or side effects for this use.