Atropine Sulfate is indicated for:

Cardiovascular disorders: Used in conditions associated with bradyarrhythmias. It is commonly administered in acute onset bradyarrhythmias. Although it may be used initially in chronic arrhythmias, long-term management usually requires cardiac pacing. It is also used for the prevention and treatment of anesthesia-related arrhythmias, drug-induced arrhythmias, and cardiac arrest due to asystole. In cases of acute myocardial infarction with bradycardia, atropine may be used cautiously, as it can potentially worsen ischemia.

Anaesthetic premedication: Administered prior to general anesthesia to reduce vagal effects on the heart and to decrease salivary and bronchial secretions.

Poisoning: Used in the treatment of anticholinesterase poisoning and certain mushroom (muscarinic) poisoning.

Reversal of neuromuscular block: Used to control muscarinic side effects of neostigmine during reversal of competitive neuromuscular blockade.

Atropine acts by competitively blocking muscarinic acetylcholine receptors, producing anticholinergic effects in various organs. It inhibits parasympathetic activity in peripheral tissues such as the heart, gastrointestinal tract, bronchial smooth muscles, iris, and secretory glands. This results in increased heart rate, reduction of vagally mediated bradycardia and heart block, relaxation of bronchial and intestinal smooth muscles, and decreased glandular secretions. Atropine also produces mydriasis (pupil dilation) and cycloplegia (loss of accommodation). Some central nervous system stimulation may occur.

In cardiovascular disorders: Typical initial doses are in the range of 0.5 to 1.0 mg intravenously. In less severe cases doses may be repeated, as necessary, upto a total dose of 0.03 mg per kg body-weight (about 2 mg); suggested dosage intervals have ranged from 3 to 5 minutes to 1 to 2 hours. In severe instances, as in asystole, a total dose of 0.04 mg per kg (about 3 mg) may be given; some authorities have recommended that the total amount should be given in three divided doses of 1 mg at 3 to 5 minute intervals whereas others consider that 3 mg should be given as a single dose.

As anaesthetic premedication: 300 to 600 mcg may be given by subcutaneous (S.C.) or intramuscular (I.M.) injection, usually 30 to 60 minutes before anaesthesia. Alternatively 300 to 600 mcg may be given intravenously immediately before induction of anaesthesia. It may also be given in combination with upto 10 mg morphine sulphate by S.C. or I.M. injection about an hour before anaesthesia.

• Suitable paediatric premedication doses are:
• Children weighing upto 3 kg: 100 mcg subcutaneously.
• Children weighing 7-9 kg: 200 mcg subcutaneously.
• Children weighing 12-16 kg: 300 mcg subcutaneously.
• Children weighing 20-27 kg: 400 mcg subcutaneously.
• Children weighing 32 kg: 500 mcg subcutaneously.
• Children weighing 41 kg: 600 mcg subcutaneously.

In anticholinesterase and mushroom poisoning: It is used in very large doses, e.g. beginning with a dose of 2 mg intravenously or intramuscularly and repeating every 5 to 15 minutes as necessary until signs and symptoms disappear. Doses of up to 100 mg may be needed in the first 24 hours, and lower oral doses should be continued to prevent reappearance of symptoms.

For control of muscarinic side-effects of neostigmine: 0.6 to 1.2 mg by intravenous injection in conjunction with neostigmine methylsulphate.

Infants and children are particularly susceptible to toxic effects of atropine.

The anticholinergic effects of atropine, both central and peripheral, may be enhanced when used with other drugs that have anticholinergic properties, such as tricyclic antidepressants, antispasmodics, antiparkinsonian agents, certain antihistamines, phenothiazines, disopyramide, and quinidine. Atropine may delay gastric emptying, which can postpone the onset of action of other medications and in some cases increase their absorption. When used with metoclopramide, atropine may further reduce lower esophageal sphincter pressure, which could help reduce the risk of aspiration of gastric contents.

Atropine is contraindicated in patients with glaucoma, chronic pulmonary disease, unstable cardiac rhythm, prostatic hypertrophy, reflux esophagitis, paralytic ileus, pyloric stenosis, and generally in elderly patients.

Common adverse effects include dry mouth, difficulty in swallowing and speaking, thirst, reduced bronchial secretions, pupil dilation (mydriasis), loss of accommodation (cycloplegia), photophobia, flushing, dry skin, transient bradycardia followed by tachycardia, palpitations, arrhythmias, difficulty in urination, and decreased gastrointestinal motility leading to constipation. Vomiting may occasionally occur.

Atropine has minimal effect on the human uterus and is not considered teratogenic. Small amounts may pass into breast milk, and it may potentially reduce milk production, although this is not well established.

Atropine Sulfate should be used with caution in children and elderly patients, as they are more susceptible to its adverse effects. It is advisable to exercise caution in patients with diarrhea. Due to the risk of hyperpyrexia, especially in hot environments or in febrile children, atropine should be used carefully. Patients with Down’s syndrome may exhibit increased sensitivity to its effects.

Caution is required in conditions associated with tachycardia such as thyrotoxicosis and heart failure, as atropine may further increase heart rate. In patients with acute myocardial infarction, it may worsen ischemia and should be used carefully. It should also be administered cautiously in patients with hypertension.

Atropine may cause mental confusion, particularly in elderly patients. Reduced bronchial secretions caused by systemic use may lead to the formation of mucus plugs. In the treatment of parkinsonism, dose adjustments should be gradual and abrupt withdrawal of antimuscarinic agents should be avoided. Minor adverse effects may be managed by reducing the dose until tolerance develops.

Anticholinergic (antimuscarinic) / Antispasmodic agent.

Store below 25°C, protected from light and moisture. Keep out of reach of children.