pralidoxime chloride 1000 MG Injection

INDICATIONS AND USAGE PROTOPAM Chloride is indicated as an antidote: (1) in the treatment of poisoning due to those pesticides and chemicals (e.g., nerve agents) of the organophosphate class which have anticholinesterase activity and (2) in the control of overdosage by anticholinesterase drugs used in the treatment of myasthenia gravis. The principal indications for the use of PROTOPAM Chloride are muscle weakness and respiratory depression. In severe poisoning, respiratory depression may be due to muscle weakness.

DOSAGE AND ADMINISTRATION Organophosphate Poisoning Treatment should include general supportive care, atropinization, and decontamination, in addition to the use of PROTOPAM Chloride. Treatment is most effective if initiated immediately after poisoning. Administration of PROTOPAM Chloride should be carried out slowly and, preferably, by infusion. If intravenous administration is not feasible, intramuscular or subcutaneous injection should be used. Generally, little is accomplished if PROTOPAM Chloride is given more than 36 hours after termination of exposure to the poison. When the poison has been ingested, it is particularly important to take into account the likelihood of continuing 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 PROTOPAM Chloride may be needed every three to eight hours. In effect, the patient should be “titrated” with PROTOPAM Chloride as long as signs of poisoning recur. As in all cases of organophosphate poisoning, care should be taken to keep the patient under observation for at least 48 to 72 hours. If dermal exposure has occurred, clothing should be removed and the hair and skin washed thoroughly with sodium bicarbonate or alcohol as soon as possible. Supportive care, including airway management, respiratory and cardiovascular support, correction of metabolic abnormalities, and seizure control, may be necessary in cases of severe organophosphate poisoning. Atropine should be given as soon as possible after hypoxemia is improved. Atropine should not be given in the presence of significant hypoxia due to the risk of atropine-induced ventricular fibrillation. In adults, atropine may be given intravenously in doses of 2 to 4 mg. This should be repeated at 5- to 10-minute intervals until full atropinization (secretions are inhibited) or signs of atropine toxicity appear (delirium, hyperthermia, muscle twitching). Some degree of atropinization should be maintained for at least 48 hours, and until any depressed blood cholinesterase activity is reversed. Use of morphine, theophylline, aminophylline, reserpine, and phenothiazine-type tranquilizers should be avoided in patients with organophosphate poisoning (see PRECAUTIONS, Drug Interactions ). Prolonged paralysis has been reported in patients when succinylcholine is given with drugs having anticholinesterase activity; therefore, it should be used with caution. After the effects of atropine become apparent, PROTOPAM Chloride may be administered. Symptoms Of Nerve Agent And Insecticide Poisoning PROTOPAM Chloride dosing is based, in part, on the severity of symptoms of nerve agent intoxication. These symptoms include the following: MILD symptoms: • Blurred vision and sore eyes • Teary eyes* • Runny nose* • Increased salivation such as sudden drooling* • 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** • Involuntary urination and defecation* • Convulsions • Unconsciousness Symptoms in INFANTS AND YOUNG CHILDREN: * These symptoms 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. ** Infants may become drowsy or unconscious, with muscle floppiness rather than muscle twitching, soon after exposure to nerve agents or pesticides. ADULT DOSING ADULT INTRAVENOUS DOSING: Refer to the Preparation for Administration section for instructions on reconstitution and dilution of PROTOPAM Chloride that result in a 10-20 mg/mL solution for intravenous infusion. Inject an initial dose of 1000 to 2000 mg of PROTOPAM Chloride, preferably as an infusion in 100 mL of normal saline, over a 15- to 30-minute period. If this is not practical or if pulmonary edema is present, the dose should be given slowly (over not less than five minutes) by intravenous injection, as a 50 mg/mL solution in water (e.g., 1000 mg in 20 mL). A second dose of 1000 to 2000 mg may be indicated after about one hour if muscle weakness has not been relieved. Additional doses may be given every 10-12 hours if muscle weakness persists. Intravenous administration of PROTOPAM Chloride should be carried out slowly and, preferably, by continuous or intermittent infusion, since temporary worsening of cholinergic manifestations (i.e. tachycardia, cardiac arrest, laryngospasm, and muscle rigidity or paralysis) may occur if PROTOPAM Chloride is infused too rapidly. The intermittent infusion rate should not exceed 200 mg/minute. If intravenous administration is not feasible, intramuscular or subcutaneous injection should be used. Evidence suggests that a loading dose followed by continuous intravenous infusion of PROTOPAM Chloride may maintain therapeutic levels longer than traditional short intermittent infusions therapy (see Pharmacokinetics ). ADULT INTRAMUSCULAR DOSING: Refer to the Preparation for Administration section for instructions on reconstitution of PROTOPAM Chloride that result in an approximate 300 mg/mL solution for intramuscular administration. Intramuscular dosing in adults should be based on the severity of clinical symptoms. MILD SYMPTOMS • For treatment of mild symptoms, administer a 600 mg (2 mL) intramuscular dose of PROTOPAM Chloride. Wait 15 minutes for PROTOPAM Chloride to take effect. • If, after 15 minutes, mild symptoms persist, then administer a second 600 mg (2 mL) intramuscular dose of PROTOPAM Chloride. • If, after an additional 15 minutes, mild symptoms continue to persist, a third 600 mg (2 mL) dose of PROTOPAM Chloride may be administered for a total cumulative dose of 1800 mg. • If at any time after the first dose, the patient develops severe symptoms, administer two additional 600 mg intramuscular doses in rapid succession for a total cumulative dose of 1800 mg of PROTOPAM Chloride. SEVERE SYMPTOMS • For treatment of severe symptoms, administer three 600 mg intramuscular doses (3 doses of 2 mL each) in rapid succession for a total dose of 1800 mg of PROTOPAM Chloride. PERSISTENT SYMPTOMS • If symptoms persist after administering the complete 1800 mg regimen (3 injections of 600 mg each), the series may be repeated beginning approximately 1 hour after administration of the last injection. PEDIATRIC DOSING (FOR PATIENTS 16 YEARS AND UNDER) PEDIATRIC INTRAVENOUS DOSING: Refer to the Preparation for Administration section for instructions on reconstitution and dilution of PROTOPAM Chloride that result in 10-20 mg/mL solution for intravenous infusion. PROTOPAM Chloride can be given as intermittent intravenous infusions or as a loading dose followed by continuous intravenous infusion, depending upon the patient’s clinical condition. The specific dose given should depend upon the severity of the symptoms. Loading Dose Following By Continuous Infusion: Administer a loading dose of 20-50 mg/kg (not to exceed 2000 mg/dose) over 15-30 minutes followed by a continuous infusion of 10-20 mg/kg/hour. Intermittent Infusion Dosing: Administer an initial intermittent infusion of 20-50 mg/kg (not to exceed 2000 mg/dose) over 15-30 minutes. A second dose of 20-50 mg/kg may be indicated after about one hour if muscle weakness has not been relieved. Repeat dosing is permissible every 10-12 hours as needed. If it is not practical to administer intermittent or continuous intravenous infusions, or if pulmonary edema is present, the 20-50 mg/kg dose should be given slowly (over not less than five minutes) by intravenous injection as a 50 mg/mL solution in water (see Preparation for Administration section). Additional doses may be given every 10-12 hours if muscle weakness

WARNINGS PROTOPAM Chloride is not effective in the treatment of poisoning due to phosphorus, inorganic phosphates, or organophosphates not having anticholinesterase activity. PROTOPAM Chloride is not indicated as an antidote for intoxication by pesticides of the carbamate class since it may increase the toxicity of carbaryl.

CONTRAINDICATIONS There are no known absolute contraindications for the use of PROTOPAM Chloride (see PRECAUTIONS, Drug Interactions and DOSAGE AND ADMINISTRATION ). Relative contraindications include known hypersensitivity to the drug and other situations in which the risk of its use clearly outweighs possible benefit.

CLINICAL PHARMACOLOGY The principal action of pralidoxime chloride is to reactivate cholinesterase (mainly outside of the central nervous system) which has been inactivated by phosphorylation due to an organophosphate pesticide or related compound. The destruction of accumulated acetylcholine can then proceed, and neuromuscular junctions will again function normally. Pralidoxime chloride also slows the process of “aging” of phosphorylated cholinesterase to a nonreactivatable form, and detoxifies certain organophosphates by direct chemical reaction. The drug has its most critical effect in relieving paralysis of the muscles of respiration. Because pralidoxime chloride is less effective in relieving depression of the respiratory center, atropine is always required concomitantly to block the effect of accumulated acetylcholine at this site. Pralidoxime chloride relieves muscarinic signs and symptoms, salivation, bronchospasm, etc., but this action is relatively unimportant since atropine is adequate for this purpose. PROTOPAM Chloride has been studied in animals as an antidote against numerous organophosphate pesticides, chemicals, and drugs (see Animal Pharmacology and Toxicology ). Regardless of whether or not animal studies suggest that the organophosphate poison to which a particular patient has been exposed is amenable to treatment with pralidoxime chloride, the use of pralidoxime chloride should, nevertheless, be considered in any life-threatening situation resulting from poisoning by these compounds, since the limited and arbitrary conditions of pharmacologic screening do not always accurately reflect the usefulness of pralidoxime chloride in the clinical situation.