Protopam Chloride

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 Chl…

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.

Drug Interactions When atropine and pralidoxime chloride are used together, the signs of atropinization (flushing, mydriasis, tachycardia, dryness of the mouth and nose) may occur earlier than might be expected when atropine is used alone. This is especially true if the total dose of atropine has been large and the administration of pralidoxime chloride has been delayed. The following precautions should be kept in mind in the treatment of anticholinesterase poisoning, although they do not bear directly on the use of pralidoxime chloride: since barbiturates are potentiated by the anticholinesterases, they should be used cautiously in the treatment of convulsions; 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 is given with drugs having anticholinesterase activity; therefore, it should be used with caution.

Pregnancy Teratogenic Effects: Animal reproduction studies have not been conducted with pralidoxime chloride. It is also not known whether pralidoxime chloride can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Pralidoxime chloride should be given to a pregnant woman only if clearly needed.

Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when pralidoxime chloride is administered to a nursing woman.

ADVERSE REACTIONS Forty to 60 minutes after intramuscular injection, mild to moderate pain may be experienced at the site of injection. Pralidoxime chloride may cause blurred vision, diplopia and impaired accommodation, dizziness, headache, drowsiness, nausea, tachycardia, increased systolic and diastolic blood pressure, hyperventilation, and muscular weakness when given parenterally to normal volunteers who have not been exposed to anticholinesterase poisons. In patients, it is very difficult to differentiate the toxic effects produced by atropine or the organophosphate compounds from those of the drug. Elevations in SGOT and/or SGPT enzyme levels were observed in 1 of 6 normal volunteers given 1200 mg of pralidoxime chloride intramuscularly, and in 4 of 6 volunteers given 1800 mg intramuscularly. Levels returned to normal in about 2 weeks. Transient elevations in creatine phosphokinase were observed in all normal volunteers given the drug. When atropine and pralidoxime chloride are used together, the signs of atropinization may occur earlier than might be expected when atropine is used alone. This is especially true if the total dose of atropine has been large and the administration of pralidoxime chloride has been delayed. Excitement and manic behavior immediately following recovery of consciousness have been reported in several cases. However, similar behavior has occurred in cases of organophosphate poisoning that were not treated with pralidoxime chloride.