Atropine is a muscarinic antagonist indicated for temporary blockade of severe or life threatening muscarinic effects.

• Atropine sulphate is for intravenous administration, but may also be administered via subcutaneous, intramuscular or via an endotracheal tube.
• Titrate according to heart rate, PR interval, blood pressure and symptoms.

Adult dosage-

• Antisialagogue or for antivagal effects: Initial single dose of 0.5 mg to 1 mg.
• Antidote for organophosporous or muscarinic mushroom poisoning: Initial single dose of  2 mg to 3 mg, repeated every 20 30 minutes.
• Bradyasystolic cardiac arrest: 1 mg dose, repeated every 3-5 minutes if asystole persists. 
• Patients with Coronary Artery Disease: Total dose should not exceed 0.03 mg/kg to 0.04 mg/kg. 

Most adverse reactions are directly related atropine’s antimuscarinic action, such as-

• Dryness of the mouth
• blurred vision
• photophobia
• tachycardia

Dry Mouth

Blurred vision

Tachycardia

• Tachycardia: When the recurrent use of atropine is essential in patients with coronary artery disease, the total dose should be restricted to 2 to 3 mg (maximum 0.03 to 0.04 mg/kg) to avoid the detrimental effects of atropine-induced tachycardia on myocardial oxygen demand.
• Acute Glaucoma: Atropine may precipitate acute glaucoma.
• Pyloric Obstruction: Atropine may convert partial organic pyloric stenosis into complete obstruction. 
• Complete Urinary Retention: Atropine may lead to complete urinary retention in patients with prostatic hypertrophy. 
• Viscid Plugs: Atropine may cause inspissation of bronchial secretions and formation of viscid plugs in patients with chronic lung disease