Pralidoxime

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Generic Name: Pralidoxime Brand Name(s): Generics only. No brands available.

Uses

What is Pralidoxime used for?

Pralidoxime is used with atropine to treat nerve agent poisoning by certain chemicals known as anticholinesterase agents (such as organophosphate pesticides such as parathion, “nerve gas” such as sarin, other nerve agents such as VX). Pralidoxime works by restoring the activity of a certain natural substance (cholinesterase) needed by nerves and muscles. Symptoms of nerve agent poisoning may include trouble breathing, headache, runny nose, drooling, vision changes, sweating, abdominal cramps, nausea, vomiting, diarrhea, muscle twitching/jerking, drowsiness, confusion, and seizures.

Pralidoxime works mostly on the muscles (including breathing muscles) to decrease twitching, cramping, weakness, and paralysis. Another medication (atropine) is used to treat these and other symptoms of nerve agent poisoning such as slow/shallow breathing, wheezing, increased sweating/saliva, abdominal cramps, vomiting, and diarrhea.

How should I take Pralidoxime?

Pralidoxime is usually given as soon as possible after the onset of poisoning or overdose symptoms. You may need to receive pralidoxime for several days.

Pralidoxime is injected into a muscle, under the skin, or into a vein through an IV. A healthcare provider will give you this injection. Pralidoxime must be given slowly. The IV infusion can take up to 30 minutes to complete.

Your breathing, blood pressure, oxygen levels, kidney function, and other vital signs will be watched closely while you are receiving this medication.

After treatment with pralidoxime, you may be watched for up to 72 hours to make sure the medicine has been effective and you no longer have any effects of the poison or drug overdose.

How do I store Pralidoxime?

Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Keep from freezing.

There may be different brands of Pralidoxime that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Pralidoxime down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Pralidoxime?

Before using pralidoxime, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, a certain nerve/muscle problem (myasthenia gravis).

This drug may make you dizzy or drowsy. Alcohol or marijuana can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

Is it safe during pregnancy or breast-feeding?

There are no adequate studies in women for determining risk when using this Pralidoxime during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Pralidoxime. Pralidoxime is pregnancy risk category N according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk,
  • B=No risk in some studies,
  • C=There may be some risk,
  • D=Positive evidence of risk,
  • X=Contraindicated,
  • N=Unknown

Side effects

What side effects can occur from Pralidoxime?

Dizziness, drowsiness, or pain at the injection site may occur. Normal effects from atropine include flushing, large pupils, fast heartbeat, and dryness of the mouth and nose. If any of these effects persist or worsen, tell your doctor, pharmacist, or other health care professional promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the life-saving benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), worsening dizziness, worsening trouble breathing.

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.

Interactions

What drugs may interact with Pralidoxime?

Pralidoxime may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with Pralidoxime?

Pralidoxime may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Pralidoxime?

Pralidoxime may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this Pralidoxime.

What is the dose of Pralidoxime for an adult?

Usual Adult Dose for Organophosphate Poisoning

Intravenous dosing (preferred route of administration):

Initial dose: 1 to 2 g, preferably as an IV infusion in 100 mL of normal saline, over 15 to 30 minutes; if an infusion is not practical or if pulmonary edema is present, the dose should be given slowly (over at least 5 minutes) by IV injection as a 50 mg/mL solution in Sterile Water for Injection (e.g., 1000 mg in 20 mL)

Second dose: 1 to 2 g may be indicated after about 1 hour if muscle weakness has not been relieved

Additional doses may be given every 10 to 12 hours if muscle weakness persists.

Intramuscular dosing (based on severity of symptoms):

MILD SYMPTOMS:

Initial dose: 600 mg IM; recommend waiting 15 minutes for pralidoxime to take effect

Second dose: 600 mg IM if mild symptoms persist after 15 minutes

Third dose: 600 mg IM (cumulative dose of 1800 mg) if mild symptoms persist after an additional 15 minutes

If severe symptoms develop at any time after the first dose, 2 additional 600 mg IM doses in rapid succession should be administered for a total cumulative dose of 1800 mg.

SEVERE SYMPTOMS: Three 600 mg IM doses in rapid succession should be administered for a total cumulative dose of 1800 mg.

PERSISTENT SYMPTOMS: If symptoms persist after administration of the complete 1800 mg regimen, the series may be repeated starting about 1 hour after the administration of the last injection.

Comments:

-The principle indications for use of this drug are muscle weakness and respiratory depression; in severe poisoning, respiratory depression may be due to muscle weakness.

-Treatment should include general supportive care, atropine, and decontamination also.

-Treatment is most effective if initiated immediately after poisoning.

-Little is accomplished if this drug is given more than 36 hours after termination of exposure to the poison.

-When poison is ingested, take into account the likelihood of continuing absorption from the lower bowel as this constitutes new exposure and fatal relapses have occurred after initial improvement; additional doses may be needed every 3 to 8 hours in this situation.

-Keep the patient under observation for at least 48 to 72 hours.

-If dermal exposure occurred, remove clothing and wash skin and hair thoroughly with sodium bicarbonate or alcohol as soon as possible.

-Provide supportive care, including airway management, respiratory and cardiovascular support, correction of metabolic abnormalities, and seizure control as needed for severe poisoning.

-Give atropine as soon as possible after hypoxemia has improved; do not give atropine if significant hypoxia is present because of the risk of atropine induced ventricular fibrillation.

-Administer atropine intravenously at doses of 2 to 4 mg, repeated at 5 to 10 minute intervals until full atropinization (secretions are inhibited) or signs of atropine toxicity appear (delirium, hyperthermia, muscle twitching).

-Maintain some degree of atropinization for at least 48 hours and until any depressed blood cholinesterase activity is reversed.

-Avoid use of morphine, theophylline, aminophylline, reserpine, and phenothiazine-type tranquilizers in organophosphate poisoning patients.

-Use succinylcholine with caution as prolonged paralysis has been reported in combination with anticholinesterases.

-Administer this drug after the effects of atropine become apparent.

Use(s): Antidote for poisoning due to pesticides and chemicals (e.g. nerve agents) of the organophosphate class that have anticholinesterase activity

Usual Adult Dose for Nerve Agent Poisoning

Intravenous dosing (preferred route of administration):

Initial dose: 1 to 2 g, preferably as an IV infusion in 100 mL of normal saline, over 15 to 30 minutes; if an infusion is not practical or if pulmonary edema is present, the dose should be given slowly (over at least 5 minutes) by IV injection as a 50 mg/mL solution in Sterile Water for Injection (e.g., 1000 mg in 20 mL)

Second dose: 1 to 2 g may be indicated after about 1 hour if muscle weakness has not been relieved

Additional doses may be given every 10 to 12 hours if muscle weakness persists.

Intramuscular dosing (based on severity of symptoms):

MILD SYMPTOMS:

Initial dose: 600 mg IM; recommend waiting 15 minutes for pralidoxime to take effect

Second dose: 600 mg IM if mild symptoms persist after 15 minutes

Third dose: 600 mg IM (cumulative dose of 1800 mg) if mild symptoms persist after an additional 15 minutes

If severe symptoms develop at any time after the first dose, 2 additional 600 mg IM doses in rapid succession should be administered for a total cumulative dose of 1800 mg.

SEVERE SYMPTOMS: Three 600 mg IM doses in rapid succession should be administered for a total cumulative dose of 1800 mg.

PERSISTENT SYMPTOMS: If symptoms persist after administration of the complete 1800 mg regimen, the series may be repeated starting about 1 hour after the administration of the last injection.

Comments:

-The principle indications for use of this drug are muscle weakness and respiratory depression; in severe poisoning, respiratory depression may be due to muscle weakness.

-Treatment should include general supportive care, atropine, and decontamination also.

-Treatment is most effective if initiated immediately after poisoning.

-Little is accomplished if this drug is given more than 36 hours after termination of exposure to the poison.

-When poison is ingested, take into account the likelihood of continuing absorption from the lower bowel as this constitutes new exposure and fatal relapses have occurred after initial improvement; additional doses may be needed every 3 to 8 hours in this situation.

-Keep the patient under observation for at least 48 to 72 hours.

-If dermal exposure occurred, remove clothing and wash skin and hair thoroughly with sodium bicarbonate or alcohol as soon as possible.

-Provide supportive care, including airway management, respiratory and cardiovascular support, correction of metabolic abnormalities, and seizure control as needed for severe poisoning.

-Give atropine as soon as possible after hypoxemia has improved; do not give atropine if significant hypoxia is present because of the risk of atropine induced ventricular fibrillation.

-Administer atropine intravenously at doses of 2 to 4 mg, repeated at 5 to 10 minute intervals until full atropinization (secretions are inhibited) or signs of atropine toxicity appear (delirium, hyperthermia, muscle twitching).

-Maintain some degree of atropinization for at least 48 hours and until any depressed blood cholinesterase activity is reversed.

-Avoid use of morphine, theophylline, aminophylline, reserpine, and phenothiazine-type tranquilizers in organophosphate poisoning patients.

-Use succinylcholine with caution as prolonged paralysis has been reported in combination with anticholinesterases.

-Administer this drug after the effects of atropine become apparent.

Use(s): Antidote for poisoning due to pesticides and chemicals (e.g. nerve agents) of the organophosphate class that have anticholinesterase activity

Usual Adult Dose for Anticholinesterase Overdose

Initial dose: 1 to 2 g IV slowly

Maintenance dose: Increments of 250 mg IV every 5 minutes as needed to control symptoms

-Solution should be diluted to 10 to 20 mg/mL

Comments:

-The principle indications for use of this drug are muscle weakness and respiratory depression; in severe poisoning, respiratory depression may be due to muscle weakness.

Use(s): Control of overdosage by anticholinesterase drugs such as neostigmine, pyridostigmine, and ambenonium, used in the treatment of myasthenia gravis

Renal Dose Adjustments

Dose adjustment(s) may be required; however, no specific guidelines have been suggested.

Precautions

CONTRAINDICATIONS:

-There are no absolute contraindications to use of this drug

-Relative contraindications include hypersensitivity to the drug and other situations where risk clearly outweighs benefit

Other Comments

Administration advice:

-Administration should be done slowly, preferably by infusion.

-If intravenous administration is not feasible, use intramuscularly or subcutaneously.

General:

-Signs of nerve agent and insecticide poisoning:

MILD SYMPTOMS:

-Blurred vision and sore eyes

-Teary eyes (this symptom is less reliable in infants and young children)

-Runny nose (this symptom is less reliable in infants and young children)

-Increased salivation such as sudden drooling (this symptom is less reliable in infants and young children)

-Chest tightness or difficulty breathing

-Tremors throughout the body or muscular twitching

-Nausea and vomiting

-Involuntary respiratory secretions

SEVERE SYMPTOMS:

-Strange or confused behavior

-Severe difficulty breathing or respiratory secretions

-Severe muscular twitching and general weakness (infants may become drowsy or unconscious, with muscle floppiness rather than twitching)

-Involuntary urination and defecation (this symptom is less reliable in infants and young children)

-Convulsions

-Unconsciousness

Patient advice:

Administer only after:

-Individual has donned a mask after recognizing a chemical agent hazard in the area.

-Some or all of the below symptoms of nerve agent poisoning are present:

–Unexplained runny nose

–Tightness of chest with difficulty breathing

–Pinpointed pupils of the eye resulting in blurred vision

–Drooling, excessive sweating

–Nausea, vomiting, and abdominal cramps

–Involuntary urination and defecation

–Jerking, twitching, and staggering

–Headache, drowsiness, coma, convulsions

–Stoppage of breathing

What is the dose of Pralidoxime for a child?

Usual Pediatric Dose for Organophosphate Poisoning

16 years and younger:

Intravenous administration (preferred method of administration):

LOADING DOSE FOLLOWED BY CONTINUOUS INFUSION

Loading dose: 20 to 50 mg/kg (maximum 2000 mg/dose) of a 10 to 20 mg/mL solution, intravenously over 15 to 30 minutes

-Follow with a continuous infusion of 10 to 20 mg/kg/hour

INTERMITTENT INFUSION

Initial dose: 20 to 50 mg/kg (maximum 2000 mg/dose) of a 10 to 20 mg/mL solution, intravenously over 15 to 30 minutes

-A second dose of 20 to 50 mg/kg may be indicated after about 1 hour if muscle weakness is not relieved.

-Repeat dosing every 10 to 12 hours as needed

-If the above dose is not practical or pulmonary edema is present, give dose diluted to a 50 mg/mL solution as a slow IV injection over at least 5 minutes

-A second 20 to 50 mg/kg dose may be given after about 1 hour if muscle weakness has not been relieved.

-Additional doses may be given every 10 to 12 hours if muscle weakness persists.

Intramuscular dosing (based on severity of symptoms):

Weight under 40 kg: 15 mg/kg per single dose; 45 mg/kg total (3 injection) dose

Weight 40 kg and above: 600 mg per single dose; 1800 mg total (3 injection) dose

MILD SYMPTOMS: Give weight appropriate dose (see above) intramuscularly; allow 15 minutes for drug to take effect

-If symptoms persist after 15 minutes, give a second dose; allow 15 minutes for drug to take effect.

-If mild symptoms persist, a third dose may be given.

-If severe symptoms develop any time after the first dose, administer two additional doses intramuscularly in rapid succession.

SEVERE SYMPTOMS: Administer three weight appropriate doses intramuscularly in rapid succession.

PERSISTENT SYMPTOMS:

-If symptoms persist after the complete regimen, the series may be repeated about 1 hour after administration of the last injection

Comments:

-The principle indications for use of this drug are muscle weakness and respiratory depression; in severe poisoning, respiratory depression may be due to muscle weakness.

-Treatment should include general supportive care, atropine, and decontamination also.

-Treatment is most effective if initiated immediately after poisoning.

-Little is accomplished if this drug is given more than 36 hours after termination of exposure to the poison.

-When poison is ingested, take into account the likelihood of continuing absorption from the lower bowel as this constitutes new exposure and fatal relapses have occurred after initial improvement; additional doses may be needed every 3 to 8 hours in this situation.

-Keep the patient under observation for at least 48 to 72 hours.

-If dermal exposure occurred, remove clothing and wash skin and hair thoroughly with sodium bicarbonate or alcohol as soon as possible.

-Provide supportive care, including airway management, respiratory and cardiovascular support, correction of metabolic abnormalities, and seizure control as needed for severe poisoning.

-Give atropine as soon as possible after hypoxemia has improved; do not give atropine if significant hypoxia is present because of the risk of atropine induced ventricular fibrillation.

-Administer atropine intravenously until full atropinization (secretions are inhibited) or signs of atropine toxicity appear (delirium, hyperthermia, muscle twitching).

-Maintain some degree of atropinization for at least 48 hours and until any depressed blood cholinesterase activity is reversed.

-Avoid use of morphine, theophylline, aminophylline, reserpine, and phenothiazine-type tranquilizers in organophosphate poisoning patients.

-Use succinylcholine with caution as prolonged paralysis has been reported in combination with anticholinesterases.

-Administer this drug after the effects of atropine become apparent.

Use(s): Antidote for poisoning due to pesticides and chemicals (e.g. nerve agents) of the organophosphate class that have anticholinesterase activity

Usual Pediatric Dose for Nerve Agent Poisoning

16 years and younger:

Intravenous administration (preferred method of administration):

LOADING DOSE FOLLOWED BY CONTINUOUS INFUSION

Loading dose: 20 to 50 mg/kg (maximum 2000 mg/dose) of a 10 to 20 mg/mL solution, intravenously over 15 to 30 minutes

-Follow with a continuous infusion of 10 to 20 mg/kg/hour

INTERMITTENT INFUSION

Initial dose: 20 to 50 mg/kg (maximum 2000 mg/dose) of a 10 to 20 mg/mL solution, intravenously over 15 to 30 minutes

-A second dose of 20 to 50 mg/kg may be indicated after about 1 hour if muscle weakness is not relieved.

-Repeat dosing every 10 to 12 hours as needed

-If the above dose is not practical or pulmonary edema is present, give dose diluted to a 50 mg/mL solution as a slow IV injection over at least 5 minutes

-A second 20 to 50 mg/kg dose may be given after about 1 hour if muscle weakness has not been relieved.

-Additional doses may be given every 10 to 12 hours if muscle weakness persists.

Intramuscular dosing (based on severity of symptoms):

Weight under 40 kg: 15 mg/kg per single dose; 45 mg/kg total (3 injection) dose

Weight 40 kg and above: 600 mg per single dose; 1800 mg total (3 injection) dose

MILD SYMPTOMS: Give weight appropriate dose (see above) intramuscularly; allow 15 minutes for drug to take effect

-If symptoms persist after 15 minutes, give a second dose; allow 15 minutes for drug to take effect.

-If mild symptoms persist, a third dose may be given.

-If severe symptoms develop any time after the first dose, administer two additional doses intramuscularly in rapid succession.

SEVERE SYMPTOMS: Administer three weight appropriate doses intramuscularly in rapid succession.

PERSISTENT SYMPTOMS:

-If symptoms persist after the complete regimen, the series may be repeated about 1 hour after administration of the last injection

Comments:

-The principle indications for use of this drug are muscle weakness and respiratory depression; in severe poisoning, respiratory depression may be due to muscle weakness.

-Treatment should include general supportive care, atropine, and decontamination also.

-Treatment is most effective if initiated immediately after poisoning.

-Little is accomplished if this drug is given more than 36 hours after termination of exposure to the poison.

-When poison is ingested, take into account the likelihood of continuing absorption from the lower bowel as this constitutes new exposure and fatal relapses have occurred after initial improvement; additional doses may be needed every 3 to 8 hours in this situation.

-Keep the patient under observation for at least 48 to 72 hours.

-If dermal exposure occurred, remove clothing and wash skin and hair thoroughly with sodium bicarbonate or alcohol as soon as possible.

-Provide supportive care, including airway management, respiratory and cardiovascular support, correction of metabolic abnormalities, and seizure control as needed for severe poisoning.

-Give atropine as soon as possible after hypoxemia has improved; do not give atropine if significant hypoxia is present because of the risk of atropine induced ventricular fibrillation.

-Administer atropine intravenously until full atropinization (secretions are inhibited) or signs of atropine toxicity appear (delirium, hyperthermia, muscle twitching).

-Maintain some degree of atropinization for at least 48 hours and until any depressed blood cholinesterase activity is reversed.

-Avoid use of morphine, theophylline, aminophylline, reserpine, and phenothiazine-type tranquilizers in organophosphate poisoning patients.

-Use succinylcholine with caution as prolonged paralysis has been reported in combination with anticholinesterases.

-Administer this drug after the effects of atropine become apparent.

Use(s): Antidote for poisoning due to pesticides and chemicals (e.g. nerve agents) of the organophosphate class that have anticholinesterase activity

How is Pralidoxime available?

Pralidoxime is available in the following dosage forms and strengths:

  • Intravenous powder for injection.

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Pralidoxime, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: April 20, 2018 | Last Modified: April 20, 2018

Sources