Can Lexapro (escitalopram) cause bradycardia?

Escitalopram (Lexapro) and Bradycardia

Yes, escitalopram (Lexapro) can cause bradycardia, particularly in elderly patients, those with pre-existing cardiac conditions, or when combined with other medications that affect heart rate.

Mechanism and Evidence

The FDA drug label for escitalopram indicates that bradycardia can occur as an adverse effect, though it is relatively uncommon. According to the FDA label, the incidence of bradycardic outliers (heart rate decreases to less than 50 bpm with a 25% change from baseline) was 0.5% in the escitalopram group compared to 0.2% in the placebo group 1.

Case reports in the literature confirm this association:

• A case report documented symptomatic bradycardia and hypotension in a 60-year-old woman taking just 20 mg/day of citalopram (a closely related SSRI) for two weeks 2
• A recent case report described repeated sinus bradycardia events in an 82-year-old female patient with cardiac dysfunction who was taking escitalopram 3

Risk Factors for Escitalopram-Induced Bradycardia

Several factors increase the risk of developing bradycardia while on escitalopram:

• Age: Patients over 65 years are at higher risk due to age-dependent reduction in drug clearance 4
• Pre-existing cardiac conditions: Particularly those with coronary heart disease 3
• Drug interactions: Concomitant use of other medications that can cause bradycardia
• Dose: Higher doses increase the risk of cardiac effects 4

Medication Interactions That Increase Bradycardia Risk

Escitalopram's bradycardia risk is amplified when combined with:

• Beta-blockers 5, 6
• Non-dihydropyridine calcium channel blockers (verapamil, diltiazem) 5, 6
• Digoxin 5, 6
• Other antidepressants with cardiac effects
• Central-acting antihypertensive drugs 5

Monitoring Recommendations

For patients taking escitalopram:

• Monitor heart rate and blood pressure in the first week of therapy and when doses are modified 2
• Consider ECG monitoring in high-risk patients, especially those receiving other medications that affect sinoatrial node function 3
• Be particularly vigilant with elderly patients (>65 years) 4
• Watch for symptoms of bradycardia: dizziness, lightheadedness, fatigue, syncope or presyncope

Management of Escitalopram-Induced Bradycardia

If bradycardia occurs:

1. Discontinue escitalopram if symptomatic bradycardia develops 3
2. Monitor cardiac parameters until normalization
3. Consider alternative antidepressants with less cardiac impact
4. For severe symptomatic bradycardia, follow standard management protocols:
   • Atropine 0.5-1 mg IV (may repeat every 3-5 minutes to maximum 3 mg) 6
   • If inadequate response, consider dopamine, isoproterenol, or epinephrine 6

Prevention Strategies

To minimize the risk of escitalopram-induced bradycardia:

• Use the lowest effective dose, especially in elderly patients
• Avoid combining with other medications that can cause bradycardia when possible 6
• Consider therapeutic drug monitoring to maintain serum concentrations below 100 nM in high-risk patients 4
• Perform baseline ECG before starting escitalopram in patients with cardiac risk factors

Conclusion

While escitalopram generally has a favorable cardiovascular safety profile compared to some other antidepressants 7, clinicians should be aware of its potential to cause bradycardia, especially in vulnerable populations. Appropriate monitoring and dose adjustment can help mitigate this risk.