Bradycardia during citalopram treatment: a case report

Area of Science:

• Pharmacology
• Cardiology
• Psychiatry

Background:

• Selective serotonin reuptake inhibitors (SSRIs) like citalopram are commonly prescribed for depression.
• Dosage adjustments are frequent in managing depression treatment.
• Cardiac side effects of SSRIs, though rare, require careful monitoring.

Observation:

• A 47-year-old woman with depression experienced a significant drop in heart rate (sinus bradycardia) to 34 beats/min.
• This event occurred 11 days after her citalopram dosage was increased from 20 mg to 40 mg daily.
• The bradycardia was asymptomatic and resolved within 24 hours of discontinuing citalopram.

Findings:

• Citalopram dose escalation was temporally associated with severe, asymptomatic sinus bradycardia.
• Citalopram blood levels remained within the therapeutic range, suggesting a pharmacodynamic rather than pharmacokinetic effect.
• Discontinuation of citalopram led to rapid resolution of the bradycardia.

Implications:

• Clinicians should be vigilant for potential cardiac side effects, including bradycardia, with citalopram, especially after dose increases.
• This case highlights the importance of cardiac monitoring in patients on SSRIs, particularly those with pre-existing cardiac conditions or on higher doses.
• Further research may be warranted to elucidate the specific mechanisms underlying citalopram-induced bradycardia.