Atropine / Pralidoxime Chloride

Pronunciation: AT-roe-peen/PRAL-i-DOX-eem KLOR-ide
Class: Antidotes

Trade Names

DuoDote
- Injection, solution 2.1 mg per 0.7 mL atropine/600 mg per 2 mL pralidoxime

Pharmacology

Atropine competitively blocks the effects of acetylcholine, including excess acetylcholine caused by organophosphorous poisoning, at muscarinic cholinergic receptors on smooth muscle, cardiac muscle, and secretory gland cells and in peripheral autonomic ganglia and the CNS.

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Pralidoxime reactivates acetylcholinesterase that has been inactivated by phosphorylation caused by an organophsphorous nerve agent or insecticide. Reactivated acetylcholinesterase hydrolyzes excess acetylcholine resulting from organophosphoruous poisoning to help restore impaired cholinergic neural function.

Pharmacokinetics

Special Populations

Pralidoxime has not been evaluated in patients with renal function impairment; however, because pralidoxime is excreted primarily in the urine, consider dosage reduction in patients with renal function impairment.

Pralidoxime has not been evaluated in patients with hepatic function impairment.

Indications and Usage

Treatment of poisoning by organophosphorous nerve agents as well as organophosphorous insecticides.

Contraindications

No absolute contraindications.

Dosage and Administration

IM Administer 1 atropine/pralidoxime injection into the mid-lateral thigh if patient experiences 2 or more mild symptoms of nerve gas or insecticide exposure. After 10 to 15 minutes, if the patient does not develop any severe symptoms of organophosphorous poisoning, no additional injections are recommended, but seek definitive medical care (eg, hospitalization, respiratory support) immediately. For emergency personnel who have administered atropine/pralidoxime, an individual decision needs to be made to determine their capacity to continue to provide emergency care. If, at any time after the first dose, the patient develops any of the severe symptoms, administer 2 additional atropine/pralidoxime injections in rapid succession, and immediately seek definitive medical care.

IM Administer 3 atropine/pralidoxime injections into the mid-lateral thigh in rapid succession and immediately seek definitive medical care. No more than 3 doses of atropine/pralidoxime should be administered unless definitive medical care is available.

General Advice

• Emergency care should include removal of oral and bronchial secretions, maintenance of a patent airway, supplemental oxygen, and, if necessary, artificial respiration.
• An anticonvulsant (eg, diazepam) may be administered to treat convulsions if suspected in an unconscious patient.
• Nerve agents and some insecticides can mask motor signs of seizures.
• Close supervision of all severely poisoned patients is indicated for at least 48 to 72 h.

Storage/Stability

Store at 59° to 86°F. Keep from freezing. Protect from light.

Drug Interactions

Avoid use in treating organophosphorous poisoning.

Effects may be potentiated; use with caution.

Reversal of neuromuscular effects of these agents may be accelerated.

May potentiate the effect of atropine, causing signs of atropinization to occur earlier than when atropine is used alone.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Asystole, atrial fibrillation, atrial flutter, cardiac syncope, flushing, MI, palpitations, premature ventricular contractions, sinus tachycardia, tachycardia, ventricular fibrillation, ventricular flutter.

Increased systolic and diastolic BP, tachycardia.

CNS

Confusion, dizziness, headache, loss of libido.

Dizziness, drowsiness, headache, impaired accommodation, muscular weakness.

Dermatologic

Maculopapular rash, petechial rash, scarletiniform rash.

Decreased sweating, dry skin, rash.

EENT

Acute angle-closure glaucoma, blurred vision, dry eyes, photophobia.

Blurred vision, diplopia.

GI

Abdominal distention, abdominal pain, constipation, dry mouth, dysphagia, nausea and vomiting, paralytic ileas.

Dry mouth, emesis, nausea.

Genitourinary

Impotence, urinary hesitancy or retention.

Decreased renal function.

Lab Tests

Elevated ALT, AST, and creatine kinase.

Local

Pain and tightness.

Miscellaneous

Anhydrosis with impaired temperature regulation; hypersensitivity reactions may include anaphylaxis, laryngospasm, and skin rash progressing to exfoliation.

Hyperventilation.

Precautions

Pregnancy

Category C .

Lactation

Excreted in breast milk.

Undetermined.

Children

Safety and efficacy not established.

Special Risk Patients

Under normal circumstances, atropine should be used with caution in elderly patients and patients with chronic pulmonary disease, disorders of heart rhythm (eg, atrial flutter), severe narrow-angle glaucoma, pyloric stenosis, prostatic hypertrophy, renal function impairment, or a recent MI.

BP

A temporary increase in BP may occur, a known effect of pralidoxime.

Complete protection against exposure

Atropine and pralidoxime should not be relied upon to provide complete protection from chemical nerve agents and insecticide poisoning.

Heat prostration

May occur with atropine, especially during vigorous physical activity when there is high ambient temperature.

Overdosage

Symptoms

Blurred vision, circulator collapse, death, dry skin and mucous membranes, fever, flushing, locomotor difficulties (including agitation, central depression, coma, confusion, delirium, disorientation, hallucinations), respiratory depression, tachycardia, widely dilated pupils that are poorly responsive to light.

Blurred vision, diplopia, dizziness, headache, impaired accommodation, nausea, slight tachycardia, transient hypertension.

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