From the Guidelines
For patients with bradycardia, the recommended dosing for atropine infusion is 0.5-1 mg IV (may be repeated every 3-5 min to a maximum dose of 3 mg) as per the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1.
Key Considerations
- Atropine is used to increase heart rate by blocking parasympathetic influences on the sinoatrial and atrioventricular nodes.
- The initial dose of atropine is typically 0.5-1 mg IV, which may be repeated every 3-5 minutes as needed, up to a maximum total dose of 3 mg.
- When transitioning to continuous infusion, the dose should be titrated based on heart rate response, starting with 0.5 mg/hour and not exceeding 1 mg/hour in most cases.
- Atropine therapy should be used as a temporizing measure while addressing the underlying cause of bradycardia or arranging for more definitive therapy such as transvenous pacing.
Important Safety Considerations
- Atropine can cause anticholinergic side effects, including confusion, urinary retention, blurred vision, and tachyarrhythmias, particularly in elderly patients who may be more sensitive to these effects.
- Atropine administration should be used cautiously in the presence of acute coronary ischemia or MI, as increased heart rate may worsen ischemia or increase infarction size, as noted in previous guidelines 1.
Administration and Monitoring
- The infusion should be administered through a central line when possible and requires cardiac monitoring throughout treatment.
- Close monitoring of the patient's heart rate and overall clinical condition is essential to adjust the atropine dose as needed and to minimize potential side effects.
From the FDA Drug Label
Titrate according to heart rate, PR interval, blood pressure and symptoms. ( 2) Adult dosage Antisialagogue or for antivagal effects: Initial single dose of 0. 5 to 1 mg. ( 2) Bradyasystolic cardiac arrest: 1 mg dose, repeated every 3 to 5 minutes if asystole persists. ( 2)
The recommended dosing for atropine infusion in patients with bradycardia is to titrate according to heart rate, PR interval, blood pressure, and symptoms. The initial single dose for antivagal effects, which may include bradycardia, is 0.5 to 1 mg. However, for bradyasystolic cardiac arrest, a dose of 1 mg is recommended, repeated every 3 to 5 minutes if asystole persists 2.
From the Research
Atropine Infusion for Bradycardia
The recommended dosing for atropine infusion in patients with bradycardia varies depending on the specific clinical scenario.
- In cases of acute myocardial infarction complicated by sinus bradycardia, a dose of 0.5 or 0.6 mg of atropine is often used 3.
- For patients with bradycardia-hypotension syndrome, selected doses of atropine may have a beneficial effect without significant complications 4.
- In the context of spinal anesthesia with dexmedetomidine sedation, a prophylactic dose of 0.5 mg atropine may be used to reduce the incidence of bradycardia 5.
Administration Considerations
When administering atropine for bradycardia, it is essential to consider the potential risks and benefits.
- Atropine may worsen bradycardia in certain cases, particularly in patients with atrioventricular blocks at the level of the His-Purkinje fibers 6.
- Higher doses of atropine (e.g., 1.0 mg) or cumulative doses exceeding 2.5 mg over 2.5 hours may increase the risk of adverse effects such as ventricular tachycardia or fibrillation, sustained sinus tachycardia, and toxic psychosis 3.
- The use of atropine should be carefully supervised, and alternative treatments such as aminophylline or theophylline may be considered in cases of atropine-resistant bradycardia 7.