Which antidepressants are safe for a patient with bradycardia?

Antidepressants Safe in Bradycardia

Selective serotonin reuptake inhibitors (SSRIs) are the safest antidepressants for patients with bradycardia, with the exception of escitalopram and citalopram which carry cardiac conduction risks and should be avoided. 1, 2

First-Line Recommendations: SSRIs (Excluding Escitalopram/Citalopram)

The safest antidepressants for bradycardia are sertraline, fluoxetine, and paroxetine—these SSRIs show no evidence of harm to cardiac conduction and may actually provide cardioprotective effects. 3, 1, 2

• Paroxetine has the lowest risk of QTc prolongation among all SSRIs and should be the preferred agent in patients with pre-existing bradycardia or other cardiac conduction abnormalities. 4

• Sertraline and fluoxetine represent intermediate-risk alternatives with favorable cardiac safety profiles and no documented effects on heart rate or conduction. 4, 3

• SSRIs as a class do not prolong cardiac conduction, cause orthostatic hypotension, or worsen bradycardia—making them dramatically safer than tricyclic antidepressants in cardiac patients. 1, 2

Antidepressants to Absolutely Avoid

Tricyclic antidepressants (TCAs) are contraindicated in bradycardia because they prolong cardiac conduction, can cause severe bradyarrhythmias requiring temporary pacing, and are the leading cause of death in antidepressant overdose. 3, 5

• A case report documented a 66-year-old patient on amitriptyline who developed severe sinus bradycardia with hemodynamic compromise requiring temporary pacemaker placement; rhythm normalized only 36 hours after drug withdrawal. 5

• TCAs frequently cause postural hypotension, raise resting heart rate paradoxically through anticholinergic effects, but simultaneously impair conduction—creating unpredictable cardiac effects in bradycardic patients. 3

Escitalopram and citalopram must be avoided in bradycardia due to documented QT prolongation and multiple case reports of escitalopram-induced sinus bradycardia, sinus arrest, and severe conduction abnormalities. 4, 6

• An 82-year-old woman developed sinus bradycardia (93.7% of heart rate <60 bpm) and sinus arrest after 3 months of escitalopram; rhythm normalized within 2 weeks of discontinuation, then recurred when escitalopram was restarted. 6

• The FDA and EMA have imposed maximum dose restrictions on escitalopram specifically due to cardiac conduction risks, particularly in patients over 60 years. 4

• Escitalopram should never be combined with other medications that slow sinus or AV nodal conduction (β-blockers, calcium-channel blockers, digoxin) without cardiology consultation. 4

Second-Line Safe Options

Mirtazapine, trazodone, and viloxazine are safe alternatives in bradycardia because they do not affect cardiac conduction, though mirtazapine should not be combined with escitalopram due to additive cardiac risks. 3, 4

• These agents are recommended when postural hypotension is undesirable, in hypertension, cardiac insufficiency, and specifically in patients with conduction abnormalities. 3

• Mirtazapine is classified as a "harmful drug" when considering hemodynamic stability broadly, but does not worsen bradycardia or conduction defects specifically. 1

Moclobemide (reversible MAOI type A) shows promise regarding cardiovascular toxicity, though traditional MAOIs carry hypertensive crisis risk and should be avoided. 3

Critical Monitoring Requirements

• Obtain a baseline 12-lead ECG before initiating any antidepressant in a bradycardic patient to evaluate for conduction abnormalities and measure QTc interval. 4

• Check for contributing factors including concomitant bradycardic medications (β-blockers, non-dihydropyridine calcium-channel blockers, digoxin, amiodarone) and electrolyte abnormalities (hypokalemia, hypomagnesemia). 4

• Monitor heart rate and blood pressure weekly for the first month, then monthly once stable, particularly in elderly patients where tricyclic-induced bradyarrhythmias are more common. 5, 7

Management of Antidepressant-Induced Symptomatic Bradycardia

If symptomatic bradycardia develops on any antidepressant, discontinue the drug immediately and administer atropine 0.5–1 mg IV every 3–5 minutes up to a maximum of 3 mg for hemodynamic compromise. 4, 7

• If atropine fails, initiate epinephrine (2–10 µg/min) or dopamine (5–10 µg/kg/min) infusion to support heart rate and blood pressure. 4, 7

• Consider transcutaneous pacing as a bridge if pharmacologic measures fail. 4, 7

Practical Algorithm for Antidepressant Selection in Bradycardia

1. First choice: Paroxetine (lowest cardiac risk among all antidepressants) 4
2. Alternative SSRIs: Sertraline or fluoxetine (intermediate risk, excellent safety profile) 4, 3
3. Non-SSRI options: Mirtazapine, trazodone, or viloxazine (safe in conduction abnormalities) 3
4. Absolutely contraindicated: All tricyclic antidepressants, escitalopram, citalopram 3, 4, 6, 5