Reviewed on 3/24/2022

What Is Atropine and How Does It Work?

Atropine is a prescription medication used for the treatment of Sialorrhea, Pylorospasm & Other Spastic Conditions of the Gastrointestinal Tract.

  • Atropine is available under the following different brand names: Atreza, Atropine PO, SalTropine

What Are Dosages of Atropine?

Adult and pediatric dosage


  • 0.4mg

Sialorrhea, Pylorospasm & Other Spastic Conditions of the Gastrointestinal Tract

Adult dosage

  • 0.4 mg orally every 4-6 hours or as needed

Pediatric dosage

  • Children weighing between 3-7 kg: 0.1 mg
  • Children weighing between 8-11 kg: 0.15 mg
  • Children weighing between  11-18 kg: 0.2 mg
  • Children weighing between 18-29 kg: 0.3 mg
  • Children weighing above 30 kg: 0.4 mg

Alternate Dosing

  • Children weighing less than 5 kg: 0.02 mg/kg/dose initially, then every 4-6 hours or as needed
  • Children weighing above 5 kg: 0.01-0.02 mg/kg orally every 4-6 hours or as needed; not less than 0.1 mg/dose, not to exceed 0.4 mg/dose

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”

What Are Side Effects Associated with Using Atropine?

Common side effects of Atropine include:

  • pain at the injection site,
  • dry mouth,
  • blurred vision,
  • sensitivity to light,
  • confusion,
  • headache,
  • dizziness,
  • rapid or irregular heart rate,
  • flushing,
  • urinary problems,
  • constipation,
  • bloating,
  • nausea,
  • vomiting,
  • loss of sex drive,
  • impotence,
  • heat intolerance, and
  • skin rash

Serious side effects of Atropine include:

  • restlessness,
  • tremor,
  • fatigue,
  • coordination difficulties,
  • confusion,
  • hallucinations,
  • depression,
  • loss of muscle control on one side,
  • sensation loss on one side of the face,
  • nausea,
  • difficulty speaking,
  • vomiting, and
  • cardiac arrest.

Rare side effects of Atropine include:

  • none 

This is not a complete list of side effects and other serious side effects or health problems that 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.


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What Other Drugs Interact with Atropine?

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 has severe interactions with no other drugs.
  • Atropine has serious interactions with the following drugs:
    • eluxadoline
    • glucagon
    • glucagon intranasal
    • glycopyrronium tosylate topical
    • macimorelin
    • pramlintide
    • revefenacin
    • secretin
    • umeclidinium bromide/vilanterol inhaled
  • Atropine has moderate interactions with at least 100 drugs.
  • Atropine has minor interactions with at least 25  drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug 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?


Effects of drug abuse

  • None

Short-Term Effects

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

Long-Term Effects

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


Pregnancy and Lactation

  • Drug readily crosses the placental barrier and enter fetal circulation; there are no adequate data on the developmental risk associated with the use of atropine in pregnant women; adequate animal reproduction studies have not been conducted with atropine.
  • Lactation
    • 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 the breastfed infant from therapy or the underlying maternal condition
Medscape. Atropine.

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