Reviewed on 11/3/2021

What Is Atropine IV/IM and How Does It Work?

Atropine IV/IM is a prescription medication used to treat the symptoms of Anesthesia Premedication, Sinus Bradycardia (ACLS), Bronchospasm, Organophosphate or Carbamate (Cholinesterase Inhibitors) Poisoning.

  • Atropine IV/IM is available under the following different brand names: AtroPen

What Are Dosages of Atropine IV/IM?

Adult and Pediatric dosage

Intramuscular device

  • 0.25mg/0.3mL
  • 0.5mg/0.7mL
  • 1mg/0.7mL
  • 2mg/0.7mL

Injectable solution

  • 0.05 mg/mL
  • 0.1mg/mL
  • 0.4mg/mL
  • 0.8mg/mL
  • 1mg/mL

Anesthesia Premedication

Adult dosage: 

  • 0.4-0.6 mg IV/IM/SC 30-60 minutes before anesthesia; repeat every 4-6 hours as needed

Pediatric dosage

  • Children weighing less than 5 kg: 0.02 mg/kg/dose 30-60 minutes preop; then every 4-6 hours as needed
  • Children weighing more than 5 kg: 0.01-0.02 mg/kg IV/IM/SC; no more than 0.4 mg

Sinus Bradycardia (ACLS)

Adult dosage

  • 0.5-1 mg or 0.04 mg/kg IV every 5 minutes, no more than 3 mg

Pediatric dosage

  • 0.02 mg/kg IV/IO every 5 minutes for 2-3 doses as needed; single dose no less than: 0.1 no more than 0.5 mg (children), 1 mg (adolescents)
  • No more than 1 mg (children), 2 mg (adolescents)


Adult dosage

  • 0.025 mg/kg in 2.5 mL NS every 6-8 hours via nebulizer; no more than 2.5 mg/dose

Pediatric dosage

  • 0.025-0.05 mg/kg in 2.5 mL NS every 6-8 hours via nebulizer; no more than 2.5 mg/dose

Organophosphate or Carbamate (Cholinesterase Inhibitors) Poisoning

Adult dosage

  • Administer 1 injection (2 mg) IM; if after the first dose, patient develops severe symptoms, administer 2 additional injections IM in rapid succession

Pediatric dosage

  • IV 0.03-0.05 mg/kg IV/IM/IO/ET every 10-20 minutes as needed to effect; then every 1-4 hours for at least 24 hours
  • IM Autoinjector: Administer one injection (2 mg) IM, if after the first dose, patient develops severe symptoms, administer 2 additional injections IM in rapid succession

Severe symptoms:

  • 3 AtroPen doses in rapid succession
  • Children weighing less than 41 kg: 2 mg/dose IM
  • Children weighing 18-41 kg: 1 mg/dose IM
  • Children weighing 6.8-18 kg: 0.5 mg/dose IM
  • Children weighing less than 6.8 kg: AtroPen formulation not recommended; administer atropine 0.05 mg/kg bradyarrhythmias

Dosage Considerations – Should be Given as Follows: 

  • See "Dosages."


About how much does an adult human brain weigh? See Answer

What Are Side Effects Associated with Using Atropine IV/IM?

Common side effects of Atropine IV/IM include:

  • fast heartbeats, 
  • pounding heartbeats, 
  • fluttering in your chest, 
  • flushing (sudden warmth, redness, or tingly feeling), 
  • urinary problems, 
  • constipation, 
  • bloating, 
  • stomach pain, 
  • nausea, 
  • vomiting, 
  • loss of interest in sex, 
  • impotence
  • dry mouth
  • dry eyes
  • blurred vision, 
  • increased sensitivity to light, 
  • confusion, 
  • dizziness, 
  • headache, and 
  • drowsiness 

Serious side effects of Atropine IV/IM include:

  • hives, 
  • difficulty breathing, 
  • swelling of the face, lips, tongue, or throat, 
  • lightheadedness
  • pounding heartbeats, 
  • fluttering in the chest, 
  • nausea, 
  • vomiting, 
  • stomach pain, 
  • feeling full after eating a small amount, 
  • blurred vision, 
  • tunnel vision
  • eye pain, 
  • seeing halos around lights, 
  • trouble swallowing, 
  • restlessness, 
  • excitement, 
  • tremors
  • problems with balance or muscle movement, 
  • increased thirst, 
  • hot and dry skin, 
  • tiredness, and
  • severe skin rash

Rare side effects of Atropine IV/IM include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Atropine IV/IM?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them.  Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first

  • Atropine IV/IM has severe interactions with no other drugs.
  • Atropine IV/IM has serious interactions with the following drugs: 
    • glycopyrronium tosylate topical
    • pramlintide
    • umeclidinium bromide/vilanterol inhaled
  • Atropine IV/IM has moderate interactions with at least 92 other drugs.
  • Atropine IV/IM has minor interactions with at least 26 other drugs. 

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drugs interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use.  Keep a list of all your medications with you, and share this information with your doctor and pharmacist.  Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

What Are Warnings and Precautions for Atropine IV/IM?


Effects of drug abuse

  • None

Short-Term Effects

  • See “What are Side Effects Associated with Using Atropine IV/IM?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Atropine IV/IM?”


Pregnancy and Lactation

  • Drug readily crosses the placental barrier and enters fetal circulation; there are no adequate data on developmental risk associated with use of atropine in pregnant women; adequate animal reproduction studies have not been conducted with atropine. 
  • Drug reported to be excreted in human milk; there are no data on effects of atropine on breastfed infant or effects on milk production; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed infant from therapy or from underlying maternal condition


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