Pralidoxime Dosage

This dosage information may not include all the information needed to use Pralidoxime safely and effectively. See additional information for Pralidoxime.

The information at Drugs.com is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.

Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for Organophosphate Poisoning

IV:
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.

IM:
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.

Usual Adult Dose for Nerve Agent Poisoning

IV:
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.

IM:
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.

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

Usual Pediatric Dose for Organophosphate Poisoning

16 years or younger:
IV:
Pralidoxime can be given as a loading dose followed by continuous IV infusion or as intermittent IV infusions, depending upon patient's clinical condition. The specific dose given should depend upon the severity of symptoms.

Loading dose: 20 to 50 mg/kg (not to exceed 2 g/dose) over 15 to 30 minutes followed by continuous infusion
Continuous infusion: 10 to 20 mg/kg/hour following the loading dose

Intermittent infusion:
Initial dose: 20 to 50 mg/kg (not to exceed 2 g/dose) over 15 to 30 minutes
Second dose: 20 to 50 mg/kg may be indicated after about 1 hour if muscle weakness has not been relieved
Repeat dosing: Permissible every 10 to 12 hours as needed.

If administration by continuous or intermittent IV infusion is not practical, or if pulmonary edema is present, the 20 to 50 mg/kg dose should be given slowly (over at least 5 minutes) by IV injection as a 50 mg/mL solution in Sterile Water for Injection. Additional doses may be given every 10 to 12 hours if muscle weakness persists.

IM:
Less than 40 kg:
Mild symptoms:
Initial dose: 15 mg/kg IM; recommend waiting 15 minutes for pralidoxime to take effect
Second dose: 15 mg/kg IM if mild symptoms persist after 15 minutes
Third dose: 15 mg/kg IM (total cumulative dose of 45 mg/kg) if mild symptoms persist after an additional 15 minutes

If severe symptoms develop at any time after the first dose, 2 additional 15 mg/kg IM doses in rapid succession should be administered for a total cumulative dose of 45 mg/kg.

Severe symptoms: Three 15 mg/kg IM doses in rapid succession should be administered for a total cumulative dose of 45 mg/kg.

Persistent symptoms: If symptoms persist after administration of the complete 45 mg/kg regimen, the series may be repeated starting about 1 hour after the administration of the last injection.

40 kg or more:
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 (total 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.

Usual Pediatric Dose for Nerve Agent Poisoning

16 years or younger:
IV:
Pralidoxime can be given as a loading dose followed by continuous IV infusion or as intermittent IV infusions, depending upon patient's clinical condition. The specific dose given should depend upon the severity of symptoms.

Loading dose: 20 to 50 mg/kg (not to exceed 2 g/dose) over 15 to 30 minutes followed by continuous infusion
Continuous infusion: 10 to 20 mg/kg/hour following the loading dose

Intermittent infusion:
Initial dose: 20 to 50 mg/kg (not to exceed 2 g/dose) over 15 to 30 minutes
Second dose: 20 to 50 mg/kg may be indicated after about 1 hour if muscle weakness has not been relieved
Repeat dosing: Permissible every 10 to 12 hours as needed.

If administration by continuous or intermittent IV infusion is not practical, or if pulmonary edema is present, the 20 to 50 mg/kg dose should be given slowly (over at least 5 minutes) by IV injection as a 50 mg/mL solution in Sterile Water for Injection. Additional doses may be given every 10 to 12 hours if muscle weakness persists.

IM:
Less than 40 kg:
Mild symptoms:
Initial dose: 15 mg/kg IM; recommend waiting 15 minutes for pralidoxime to take effect
Second dose: 15 mg/kg IM if mild symptoms persist after 15 minutes
Third dose: 15 mg/kg IM (total cumulative dose of 45 mg/kg) if mild symptoms persist after an additional 15 minutes

If severe symptoms develop at any time after the first dose, 2 additional 15 mg/kg IM doses in rapid succession should be administered for a total cumulative dose of 45 mg/kg.

Severe symptoms: Three 15 mg/kg IM doses in rapid succession should be administered for a total cumulative dose of 45 mg/kg.

Persistent symptoms: If symptoms persist after administration of the complete 45 mg/kg regimen, the series may be repeated starting about 1 hour after the administration of the last injection.

40 kg or more:
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 (total 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.

Renal Dose Adjustments

Renally impaired patients may have increased plasma pralidoxime levels. The manufacturer suggests a dosage reduction; however, there is insufficient information with which to make a recommendation.

Liver Dose Adjustments

Data not available

Dose Adjustments

When the organophosphate poison has been ingested, it is especially important to account for the probability of continued absorption from the lower bowel since this constitutes new exposure and fatal relapses have been reported after initial improvement. In such cases, additional doses of pralidoxime may be needed every 3 to 8 hours. Effectively, the patient should be "titrated" with pralidoxime as long as signs of poisoning recur.

A loading dose followed by continuous IV infusion of pralidoxime may maintain therapeutic levels longer than traditional short intermittent infusion therapy.

Precautions

In addition to the use of pralidoxime, treatment of organophosphate poisoning should include general supportive care, atropinization, and decontamination. Pralidoxime must be given as soon as possible after the exposure (within 36 hours) to be effective. Care should be taken to keep the patient under observation for at least 48 to 72 hours in all cases of organophosphate poisoning.

In organophosphate poisoning, atropine (2 to 4 mg IV every 5 to 10 minutes in adults) should be initiated as soon as possible after hypoxemia has improved. Atropine should be repeated until full atropinization or signs of atropine toxicity appear. Some degree of atropinization should be maintained for at least 48 hours, and until any depressed blood cholinesterase activity is reversed. Pralidoxime may be administered after the effects of atropine become apparent.

IV administration of pralidoxime should be slow and, preferably, by continuous or intermittent infusion. Transient worsening of cholinergic symptoms may occur if the infusion is too rapid. The intermittent infusion rate should not exceed 200 mg/minute. If IV administration is not feasible, IM or subcutaneous injection should be used.

Morphine, theophylline, aminophylline, reserpine, and phenothiazine-type tranquilizers should be avoided in patients with organophosphate poisoning. Prolonged paralysis has been reported in patients when succinylcholine was given with drugs having anticholinesterase activity; therefore, it should be used with caution.

Pralidoxime is not effective in the treatment of poisoning due to phosphorus, inorganic phosphates, or organophosphates without anticholinesterase activity. It is not indicated as an antidote for intoxication by carbamate pesticides.

Dialysis

Data not available

Other Comments

Pralidoxime dosing is partly based on the severity of symptoms of nerve agent intoxication. Symptoms of nerve agent and insecticide poisoning include:

Mild symptoms: Blurred vision and sore eyes, teary eyes, runny nose, increased salivation such as sudden drooling, chest tightness or difficulty breathing, tremors throughout 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 muscle twitching, soon after exposure to nerve agents or pesticides), involuntary urination and defecation, convulsions, unconsciousness

Teary eyes, runny nose, increased salivation such as sudden drooling, and involuntary urination and defecation are sometimes observed in healthy infants and young children. In this age group, these symptoms are less reliable than other symptoms listed. Symptoms must be considered collectively when nerve agent or pesticide exposure is known or suspected.

IM injections in children should be administered in the anterolateral aspect of the thigh to avoid the nerve, artery, and vein, as well as the femur.

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