Atropine

Question 1

Class

Answer 1

Anticholinergic agent

Question 2

Mechanism of action

Answer 2

Inhibits action of acetylcholine at postganglionic parasympathetic receptor sites. (Increases heart rate);
Antagonizes excess muscarinic receptor stimulation caused by organophosphate insecticides and chemical nerve agents

Question 3

Onset and duration

Answer 3

Onset: Rapid
Duration: 2-6 hours

Question 4

Indications

Answer 4

Hemodynamically significant bradycardia; organophosphate or nerve gas poisoning

Question 5

Contraindications

Answer 5

Tachycardia; Hypersensitivity; use with caution in patients with myocardial ischemia and hypoxia; hypothermic bradycardia; obstructive disease of the GI tract; obstructive uropathy; unstable cardiovascular status in acute hemorrhage; narrow-angle glaucoma; thyrotoxicosis

Question 6

Adverse reactions

Answer 6

Tachycardia; paradoxical bradycardia when pushed to slowly or when adult dose is <0.5mg; palpitations; dysrhythmias; headache; dizziness; dry mouth/nose/skin; nausea and vomiting; flushed, hot, dry skin; allergic reactions

Question 7

Drug interactions

Answer 7

Use with other anticholinergic agents may increase Vagal blockade; adverse effects may occur when administered with digitalis, cholinergics, or neostigmine; effects may be enhanced by antihistamines, antipsychotics and antidepressants

Question 8

How supplied

Answer 8

Usually supplied in prefilled syringes containing 1mg in 10mL

Question 9

Bradycardia dosage and administration

Answer 9

Adult: 0.5mg q3-5 minutes(max total dose 3mg)
Pediatric: 0.02 mg/kg IV/IO minimum dose of 0.1mg max dose 0.5, may be repeated once, max total dose 1mg for child; 3mg adolescent; ET dose is 0.04-0.06 mg/kg

Question 10

Anticholinesterase poisoning dosage and administration

Answer 10

Adult: 1-2mg IV push q 5-15 minutes until atropine effects are observed.
Pediatric: <12 years 0.05mg/kg Iv/IO, may be repeated doubling the dose q 20-30 minutes until symptoms reverse;

> 12 years 1mg Iv/IO, then doubling dose q 5minutes until symptoms reverse

Question 11

Special considerations

Answer 11

Atropine dilates pupils, rendering them nonreactive.

Atropine is not effective in heart transplantation patients