Pregnancy Classes

• Blocks acetylcholine at parasympathetic sites in smooth muscle, secretory glands, and the CNS
• Decreases vagal tone resulting in increased heart rate (chronotropic) and AV conduction (dromotropic)
• Dries secretions and relaxes smooth muscles in bronchioles
• Reverses the muscarinic effects of cholinergic poisoning due to agents with acetylcholinesterase inhibitor activity by acting as a competitive antagonist of acetylcholine at muscarinic receptors.

• Symptomatic bradycardia
• Organophosphate or carbamate insecticide or nerve agent poisoning: Antidote for anticholinesterase poisoning

• None

Adult

IV, IM, IO: 0.5 every 3 to 5 minutes

Pediatric

IV, IM, IO: 0.05 mg/kg/dose; minimum dose: 0.1 mg/dose, maximum dose: 0.5 mg/dose; may repeat once in 5 minutes

IV: Administer undiluted by rapid IV injection

IM (AtroPen)

Rapid

≤4 hours

• Heart transplant: Atropine is ineffective in heart transplant recipients due to lack of vagal innervation and likely not effective for type II second-degree or third-degree atrioventricular node block.
• Cardiovascular disease: Use with caution in patients with myocardial ischemia, heart failure and tachyarrhythmias due to blood pressure increases and tachycardia causing increased myocardial oxygen demand.
• Administration: Administer by rapid IV injection; slow injection may result in paradoxical bradycardia by stimulation of the vagal nerve.
• Organophosphate and carbamate poisoning: Use the mneumonic DUMBELS for the symptoms of organophosphate poisoning – Defecation, Urination, Miosis, Bronchorrhea/Bronchospasm/Bradycardia, Emesis, Lacrimation, Salivation. Common organophosphate/carbamates include bug bombs, roach and ant sprays.

• Cardiovascular
  • Tachycardia, Palpitations, Arrhythmias
• Nervous System
  • Drowsiness, Confusion, Headache
• Dermatologic
  • Dry and hot skin, erythematous rash, Anhidrosis (decreased sweating), Hyperthermia
• Respiratory
  • Tachypnea, pulmonary edema
• Ophthalmic
  • Blurred vision, mydriasis (pupillary dilation)
• Gastrointestinal
  • Xerostomia (dry mouth), constipation, ileus (impaired GI motility), nausea/vomiting
• Genitourinary
  • Urinary retention