Atropine + Pralidoxime

Indications

Atropine + Pralidoxime is used for: Organophosphate Poisoning

Adult Dose

Organophosphate Poisoning Indicated for treatment of poisoning by organophosphorus nerve agents as well as organophosphorus insecticides in adults and pediatric patients weighing >41 kg (90 pounds) 2.1 mg atropine/0.7 mL + 600 mg pralidoxime/2 mL IM Maximum dose: Not to exceed 3 injections unless medical care support available 3 autoinjectors should be available for use in each patient (including healthcare providers) at risk for organophosphorus poisoning; use 1 for mild symptoms plus 2 more for severe symptoms See also Administration Mild symptoms >2 mild symptoms: 1 injection IM; if after 10-15 min there are no severe symptoms experienced, no further injections are necessary Additional doses: If, at any time following the first injection, the patient develops any of the severe symptoms, administer 2 additional IM injections in rapid succession Mild symptoms: Bradycardia, chest tightness, breathing difficulties, blurred vision, increased salivation (eg, sudden drooling), miosis, nausea or vomiting, runny nose, stomach cramps (acute onset), salivation, teary eyes, wheezing/coughing, tremors/muscular twitching, airway secretions increased Severe symptoms Any severe symptom listed below: 3 injections IM in rapid succession Severe symptoms: Confused/strange behavior, involuntary urination/defecation, muscular twitching/generalized weakness (severe), severe breathing difficulties or copious secretion from lung or airway, convulsions, unconsciousness Hepatic impairment Patients with severe hepatic impairment may require less frequent doses after initial dose

Child Dose

Organophosphate Poisoning Indicated for treatment of poisoning by organophosphorus nerve agents as well as organophosphorus insecticides in adults and pediatric patients weighing >41 kg (90 pounds) <41 kg: Safety and efficacy not established >41 kg: 2.1 mg atropine/0.7 mL + 600 mg pralidoxime/2 mL IM Maximum dose: Not to exceed 3 injections unless medical care support available 3 autoinjectors should be available for use in each patient (including healthcare providers) at risk for organophosphorus poisoning; use 1 for mild symptoms plus 2 more for severe symptoms Mild symptoms >2 mild symptoms: 1 injection IM; if after 10-15 min there are no severe symptoms experienced, no further injections are necessary Additional doses: If, at any time following the first injection, the patient develops any of the severe symptoms, administer 2 additional IM injections in rapid succession Mild symptoms: Bradycardia, chest tightness, breathing difficulties, blurred vision, increased salivation (eg, sudden drooling), miosis, nausea or vomiting, runny nose, stomach cramps (acute onset), salivation, teary eyes, wheezing/coughing, tremors/muscular twitching, airway secretions increased Severe symptoms Any severe symptom listed below: 3 injections IM in rapid succession Severe symptoms: Confused/strange behavior, involuntary urination/defecation, muscular twitching/generalized weakness (severe), severe breathing difficulties or copious secretion from lung or airway, convulsions, unconsciousness

Renal Dose

Renal impairment Pralidoxime can cause decreased renal function Patients with severe renal impairment may require less frequent doses after initial dose

Administration

IM Administration Administer IM in the lateral thigh muscle or buttocks

Contra Indications

Precautions

Caution in patients with known cardiovascular disease or cardiac conduction problems May inhibit sweating and lead to hyperthermia; avoid excessive exercise and heat exposure Caution in susceptible individuals at risk for acute glaucoma Caution in patients with bladder outflow obstruction owing to risk of urinary retention Caution with partial pyloric stenosis because of risk of complete pyloric obstruction May cause inspiration of bronchial secretions and formation of dangerous viscid plugs in individuals with chronic lung disease; monitor respiratory status Individual should not rely solely upon atropine and pralidoxime to provide complete protection from chemical nerve agents and insecticide poisoning (eg, primary protection is the wearing of protective garments) Elderly individuals may be more susceptible to the effects of atropine Patients with organophosphorus nerve agent or organophosphorus insecticide poisoning who have received atropine/pralidoxime may exhibit accelerated reversal of the neuromuscular blocking effects of succinylcholine and mivacurium; monitor for neuromuscular effects with concomitant succinylcholine or mivacurium use

Pregnancy-Lactation

Pregnancy Atropine readily crosses the placental barrier and enters fetal circulation; there are no adequate data on developmental risk associated with use of atropine, pralidoxime, or combination in pregnant women Lactation Atropine has been reported to be excreted in human milk; unknown whether pralidoxime is excreted in human milk

Interactions

Adverse Effects

Side effects of Atropine + Pralidoxime : Frequency Not Defined Injection site reaction (muscle tightness, pain) Atropine Dry mouth Blurred vision Dry eyes Photophobia Confusion Headache Dizziness Pralidoxime Vision changes Dizziness, headache Drowsiness Nausea Tachycardia Increased blood pressure Muscular weakness Dry mouth Emesis Rash Dry skin Hyperventilation Decreased renal function Manic behavior Transient elevation of LFTs

Mechanism of Action

Atropine: Competitively blocks the effects of acetylcholine, including excess acetylcholine due to organophosphorus poisoning, at muscarinic cholinergic receptors on smooth muscle, cardiac muscle, secretory gland cells, and in peripheral autonomic ganglia and the central nervous system Pralidoxime: Reactivates acetylcholinesterase which has been inactivated by phosphorylation due to an organophosphorous nerve agent or insecticide; reactivated acetylcholinesterase hydrolyzes excess acetylcholine, which is clinically important because only a small proportion of active acetylcholinesterase is needed to maintain vital functions