Indications Pradox (Pralidoxime Chloride) is indicated as an antidote in the treatment of poisoning caused by organophosphate pesticides and chemicals that inhibit cholinesterase activity. It is also used to manage overdose of anticholinesterase drugs used in myasthenia gravis. The main indications include muscle weakness and respiratory depression, which may result from severe poisoning.

Pharmacology Pralidoxime Chloride reactivates acetylcholinesterase that has been inactivated by organophosphate compounds. This restores normal neuromuscular function by allowing the breakdown of accumulated acetylcholine. It also slows the aging of phosphorylated cholinesterase and detoxifies certain organophosphates. The drug is most effective in relieving paralysis of respiratory muscles. Atropine must be administered concurrently to block excess acetylcholine. Pharmacokinetics: Minimum therapeutic plasma concentration (4 µg/ml) is reached within about 16 minutes after a 600 mg injection. It is rapidly excreted in urine, partly unchanged and partly metabolized by the liver.

Dosage & Administration Adults and children over 16 years: Initial dose 1000–2000 mg by infusion in 100 ml normal saline over 15–30 minutes. If infusion is not practical, inject slowly (not less than 5 minutes) as 50 mg/ml solution. A second dose may be given after 1 hour if muscle weakness persists. Additional doses may be repeated every 10–12 hours. Children under 16 years: Loading dose 20–50 mg/kg (maximum 2000 mg/dose) over 15–30 minutes. Maintenance infusion 10–20 mg/kg/hour or repeat bolus every 10–12 hours as needed. Preparation: Reconstitute 1000 mg vial with 20 ml normal saline (50 mg/ml), then dilute further to 10–20 mg/ml for infusion. Discard unused solution.

Interaction Concurrent use with atropine may cause earlier signs of atropinization (flushing, mydriasis, tachycardia, dryness of mouth and nose), especially if atropine dose is large or Pradox administration is delayed.

Contraindications Contraindicated in patients hypersensitive to any component of the product.

Side Effects Rapid injection may cause tachycardia, laryngospasm, or muscle rigidity.

Pregnancy & Lactation Pregnancy Category C. Use only if clearly needed. Unknown if excreted in human milk; caution advised in nursing women.

Precautions & Warnings Avoid barbiturates, morphine, theophylline, aminophylline, succinylcholine, reserpine, and phenothiazine-type tranquilizers in organophosphate poisoning. Succinylcholine may cause prolonged paralysis when combined with anticholinesterase drugs.

Overdose Effects Symptoms include dizziness, blurred vision, diplopia, headache, nausea, and mild tachycardia. Treatment involves artificial respiration and supportive care.

Therapeutic Class Antidote preparations.