Atropine sulfate

, medical expert
Last reviewed: 07.06.2024

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Atropine sulfate is a medication that is a derivative of the alkaloid of belladonna, a plant in the nightshade family. Atropine sulfate has the ability to block muscarinic-type receptors for acetylcholine, resulting in a parasympathetic block. As a result, it has a variety of pharmacological effects on the body.

Atropine sulfate can be used in medical practice for a variety of purposes:

  1. Pupil dilation (mydriasis): Atropine is used in ophthalmology to dilate the pupil, allowing the doctor to examine the back of the eye in more detail.
  2. Reduction of salivary and sweat gland secretion: This property of atropine may be useful in surgery to reduce the patient's salivary secretion or reduce sweating.
  3. Reduction of gastric juice secretion: Atropine may be used as a component of combination therapies to treat or prevent excessive gastric juice secretion, such as in peptic ulcer disease.
  4. Reduction of intestinal peristalsis: This property of atropine may be useful in the treatment of irritable bowel syndrome or diarrhea.
  5. Reduction of bronchial gland secretion: Atropine can be used to reduce secretion in the bronchi in diseases of the respiratory system.
  6. Cardiopulmonary recovery: Atropine is sometimes used as part of cardiopulmonary recovery protocols for asystole or bradycardia.

It is important to note that atropine sulfate is a powerful drug with potentially serious side effects and its use should be supervised by a physician.

Indications Atropine sulfate

  1. Mydriasis (pupil dilation): Atropine is used in ophthalmology for mydriasis in medical procedures such as eye exams or treatment of certain eye diseases.
  2. Bronchodilation: In some cases, atropine may be used to dilate the bronchi and facilitate breathing in patients with bronchospasm, such as in obstructive lung diseases such as bronchial asthma or chronic obstructive pulmonary disease (COPD).
  3. Gastrointestinal disorders: Atropine may be used to reduce gastric juice secretion and decrease intestinal peristalsis, which may be useful in peptic ulcer disease or irritable bowel syndrome.
  4. Reduction of salivary gland secretion: This property of atropine can be used in surgery to reducesalivary secretion in patients.
  5. Cardiopulmonary Recovery: Atropine may be used in cardiopulmonary recovery protocols to increase heart rate and improve cardiac conduction in asystole or bradycardia.

Release form

  1. Solution for injection:

    • This is the most common form of atropine used in clinical settings.
    • Solutions are typically available in concentrations of 0.1 mg/mL or 1 mg/mL.
    • The solution is intended for intravenous (IV), intramuscular (IM), or subcutaneous (SC) administration.
  2. Eye drops:

    • Used to dilate the pupils for diagnostic procedures in ophthalmology or to treat intraocular inflammation.
    • Usually contain a concentration of atropine between 0.5% and 1%.
  3. Pills:

    • Although the tablet form of atropine is less common, it can also be used for systemic treatment in certain medical scenarios.
    • Tablets may contain varying amounts of atropine, such as 0.25 mg or 0.5 mg.


  1. Blocking muscarinic receptors:

    • Atropine sulfate is a strong antagonist of muscarinic receptors, which are located in various tissues and organs such as the heart, blood vessels, GI tract, urinary system, respiratory tract, and eyes.
    • Blocking muscarinic receptors results in decreased responses to acetylcholine stimulation, which can alter the function of these organs and systems.
  2. Cardiotonic effect:

    • In low doses, atropine sulfate can cause an increase in heart rate by blocking the heart's muscarinic receptors, resulting in an increase in cardiac output.
    • However, in large doses, atropine sulfate may cause tachycardia and arrhythmias due to its excitatory effect on the heart.
  3. Relaxation of smooth muscles:

    • Blocking muscarinic receptors in the smooth muscles of the GI tract, bronchi and other organs leads to their relaxation.
    • It can be useful in treating spasms, asthma, colic, and other symptoms associated with overactive smooth muscles.
  4. Pupil dilation:

    • Atropine sulfate blocks muscarinic receptors in the eye, causing pupil dilation (mydriasis).
    • This property can be used for medical purposes, such as performing an eye exam or treating certain eye conditions.
  5. Decreased secretion:

    • Blocking of muscarinic receptors in mucosal glands leads to decreased secretion of salivary, sweat, gastrointestinal and other glands.


  1. Absorption: Atropine sulfate can be administered in various forms including oral, intranasal, injectable and topical. After oral administration, absorption of atropine sulfate is usually slow and incomplete from the gastrointestinal tract.
  2. Distribution: Atropine sulfate has high affinity to plasma proteins, which may affect its distribution in the body. It can also penetrate the blood-brain barrier and the placental barrier.
  3. Metabolism: Atropine sulfate is metabolized in the liver, mainly through hydrolysis by hydrolases. Metabolites of atropine sulfate may also have anticholinergic activity.
  4. Excretion: Most of atropine sulfate is excreted with urine as metabolites. The plasma concentration of atropine decreases rapidly after administration.
  5. Excretionhalf-life: The half-life of atropine sulfate from the body is about 2-3 hours.

Dosing and administration

Method of Application:

  • Injections: Atropine sulfate is most commonly administered intravenously (IV), intramuscularly (IM) or subcutaneously (SC). The choice of route of administration depends on the clinical situation and the desired speed of effect.
  • Eye drops: Used for topical application in ophthalmology to dilate the pupil or reduce intraocular inflammation.
  • Tablets: Take orally with water, preferably one hour before a meal or 2 hours after a meal to improve absorption.



  • Adults:
    • For bradycardia: The usual starting dose is 0.5 mg IV, repeated every 3 to 5 minutes until the desired effect is achieved. The maximum dose is up to 3 mg.
    • As an antidote for poisoning: Initial dose is 1-2 mg IV, repeated according to clinical need. Doses may be significantly increased depending on the degree of poisoning.
  • Children:
    • Dosage is based on body weight, usually 0.02 mg/kg intravenously, repeated as needed every 15-30 minutes.

Eye drops:

  • The dosage depends on the purpose of use, but the drops are usually administered 1-2 times a day, 1-2 drops in each eye. The dosage may be adjusted depending on the response to treatment and medical advice.


  • When using the tablet form, the dosage will depend on the specific disease and the form of the drug, and should be determined by the attending physician.

Use Atropine sulfate during pregnancy

The use of atropine sulfate during pregnancy requires caution as the effects on the fetus are not fully understood. Atropine crosses the placenta and may potentially affect the developing fetus.

Possible Risks:

  1. Teratogenic Effects: There is no evidence of significant teratogenic effects of atropine in humans, but animal studies have shown possible risks.
  2. Physiologic effects on the fetus: Theoretically, atropine can cause the same effects on the fetus as on an adult, including an increase in heart rate.


  • FDA Classification: Atropine is classified as Category C by the FDA for use during pregnancy. This means that animal studies have identified some risks to the fetus, but there have been no adequate and well-controlled studies in pregnant women.
  • Use: Atropine should be used during pregnancy only when the potential benefit to the mother outweighs the potential risks to the fetus. For example, atropine may be used in emergency situations such as bradycardia or organophosphate poisoning where its use may be life-saving.
  • Consultation with your doctor: Pregnant women should discuss all risks and benefits of atropine with their doctor and consider possible alternatives.

During pregnancy, atropine is used with caution and only when its use is justified by clinical indications, with careful weighing of all potential risks and benefits.


  1. Glaucoma: The use of atropine sulfate can increase intraocular pressure, which can be dangerous for people with glaucoma.
  2. Asthma attacks: People with asthma should avoid atropine sulfate as it can worsen attacks of shortness of breath and other symptoms.
  3. Prostatic hypertrophy: Atropine sulfate may worsen symptoms of this condition, such as difficulty urinating.
  4. Gastrointestinal diseases: The medicine may aggravate some gastrointestinal health problems, such as constipation or intestinal atony.
  5. Cardiac arrhythmias: The use of atropine sulfate may worsen some types of arrhythmias.
  6. Pregnancy and breastfeeding: During pregnancy and breastfeeding, the use of atropine sulfate may be unsafe or require consultation with a physician.
  7. Individual intolerance: People with known individual intolerance to atropine should avoid its use.

Side effects Atropine sulfate

  1. Drowsiness and fatigue: Many patients may experience drowsiness, fatigue, or general weakness while taking atenolol.
  2. Cold extremities: Some people may experience a cold sensation in the hands and feet due to constriction of blood vessels.
  3. Dry throat or nose: Dry throat or nose may occur.
  4. Decreased sexual desire: Dec reased sexual desire or erectile dysfunction may occur in some patients while taking atenolol.
  5. Bradycardia: This is a condition in which the heart rate drops to lower values, which can cause feelings of fatigue or dizziness.
  6. Headache: Some patients may experience headaches or dizziness.
  7. Nonspecific complaints: These include vague symptoms such as nausea, abdominal pain, or general malaise.
  8. Decrease in blood pressure: When using atenolol, a decrease in blood pressure may occur, which may lead to dizziness or a feeling of weakness.
  9. Specific side effects: Include bronchospasm (worsening of respiratory function in asthmatics), masking hypoglycemia (masking symptoms of low blood sugar in diabetic patients), increased reaction to allergens, and others.


  1. Tachycardia and arrhythmias: Overdose of atropine sulfate may cause palpitations (tachycardia) and arrhythmias due to the excitatory effects on the cardiac system.
  2. Hypertension: Excessive action of atropine sulfate can lead to an increase in blood pressure (hypertension), which can cause dizziness, headache and even the development of vascular complications.
  3. Dry mouth and gastrointestinal disorders: Blocking muscarinic receptors may cause dry mouth, decreased gastric juice secretion and other GI disorders such as constipation.
  4. Convulsionsand agitation: Possible consequences of overdose may include convulsions, nervousness and agitation due to the excitatory effect of atropine on the central nervous system.
  5. Mydriasis: Overdose of atropine sulfate may cause significant dilation of the pupils (mydriasis), which may lead to visual disturbance and photophobia.
  6. Respiratory arrest: In case of severe overdose atropine sulfate may suppress the respiratory center and cause respiratory arrest.

Interactions with other drugs

  1. Anticholinergic drugs: Use of atropine sulfate with other anticholinergic drugs such as antidepressants, antihistamines, or antispasmodics may result in a stronger anticholinergic effect and increase the risk of side effects such as dry mouth, constipation, difficulty urinating, etc.
  2. Anticholinesterase drugs: The use of atropine sulfate with anticholinesterase drugs such as pyridostigmine or physostigmine may result in decreased efficacy of the latter and worse control of symptoms of myasthenia gravis or other neuromuscular blockers.
  3. Antiarrhythmic drugs: The use of atropine sulfate with antiarrhythmic drugs such as aminodarone may increase the risk of tachycardia and arrhythmias, especially in patients with a predisposition to cardiac arrhythmias.
  4. Glaucoma medications: The use of atropine sulfate with glaucoma medications such as timolol or dorzolamide may increase intraocular pressure and worsen the condition of patients with glaucoma.
  5. Sedative drugs: The use of atropine sulfate with sedative drugs, such as benzodiazepines or hypnotics, may increase the sedative effect and increase the risk of drowsiness and impaired coordination of movements.
  6. Parkinsonism medications: Use of atropine sulfate with parkinsonism medications such as levodopa or carbidopa may reduce their effectiveness and worsen parkinsonism symptoms.


To simplify the perception of information, this instruction for use of the drug " Atropine sulfate" translated and presented in a special form on the basis of the official instructions for medical use of the drug. Before use read the annotation that came directly to medicines.

Description provided for informational purposes and is not a guide to self-healing. The need for this drug, the purpose of the treatment regimen, methods and dose of the drug is determined solely by the attending physician. Self-medication is dangerous for your health.

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