What is the treatment for a citalopram (escitalopram) overdose?

Treatment of Citalopram Overdose

Establish airway, provide supportive care with cardiac monitoring, administer activated charcoal if presenting early, give sodium bicarbonate for QRS widening or QTc prolongation, and monitor for seizures and serotonin syndrome. 1

Immediate Stabilization and Airway Management

• Secure and maintain an airway to ensure adequate ventilation and oxygenation as the first priority in any citalopram overdose 1
• Gastric evacuation by lavage should be considered in early presentations, followed by activated charcoal administration 1, 2
• Establish continuous cardiac and vital sign monitoring immediately upon presentation 1

Cardiac Toxicity Management

ECG Monitoring and Sodium Bicarbonate Therapy

• Administer sodium bicarbonate (1-2 mEq/kg of 8.4% solution) for QRS prolongation >120 ms or significant QTc prolongation, as citalopram causes sodium channel blockade similar to tricyclic antidepressants 3, 4
• Monitor for QTc prolongation, which is the most significant cardiac risk with citalopram overdose, particularly at doses >600 mg 5, 6
• Watch for progression to torsades de pointes, which has been reported in severe overdoses and can be fatal 6, 2
• Continue sodium bicarbonate infusion if initial bolus resolves ECG abnormalities, maintaining close monitoring for recurrence 4

Specific Cardiac Considerations

• Citalopram overdoses can present with sinus tachycardia, ventricular arrhythmias, nodal rhythm, and in severe cases, torsades de pointes progressing to cardiac arrest 1, 6
• Consider ECMO for refractory shock or cardiac arrest due to sodium channel blocker toxicity, though this is based on case reports 3
• Forced diuresis, dialysis, and hemoperfusion are unlikely to be beneficial due to citalopram's large volume of distribution 1

Neurologic Complications

Seizure Management

• Monitor closely for seizures, which can occur even with delayed presentations (up to 13 hours post-ingestion) 4, 7
• Seizures are more common with ingestions >600 mg and represent a major cause of morbidity 6, 7
• Implement seizure precautions for all moderate to severe citalopram overdoses 7

Serotonin Syndrome Recognition and Treatment

• Watch for serotonin syndrome manifestations: altered mental status, neuromuscular hyperactivity (increased muscle tone, clonus), autonomic instability (hyperthermia, tachycardia), and diaphoresis 6, 8
• Severe hyperthermia (up to 41.8°C) can develop rapidly and requires aggressive cooling measures 6
• Administer cyproheptadine for suspected serotonin syndrome (initial dose 12 mg, then 2 mg every 2 hours if symptoms persist, maximum 32 mg/day) 6
• Provide aggressive sedation with benzodiazepines for severe neuromuscular hyperactivity 6, 8

Severity Assessment and Disposition

Risk Stratification by Dose

• Ingestions <600 mg typically produce mild to moderate symptoms 6
• Ingestions >600 mg carry significant risk for severe manifestations including QTc prolongation, torsades de pointes, seizures, and serotonin syndrome 6, 7
• Therapeutic citalopram levels are 9-200 ng/mL; toxic levels can exceed 7300 ng/mL in fatal cases 6

Hospital Admission Criteria

• Admit all patients with moderate to severe citalopram overdose to intensive care with continuous cardiac monitoring 7
• Median hospital stay is 3 days (range 1-8 days) for significant overdoses 7
• Symptoms can be protracted, requiring up to 14 days of critical care in severe cases, particularly in patients with abnormal CYP2C19 metabolism 8

Common Clinical Presentations

The most frequently reported symptoms include:

• Drowsiness and decreased consciousness (common) 7
• Tachycardia (very common, occurring in >50% of cases) 7
• QTc prolongation (approximately 30% of cases) 7
• Seizures (approximately 15% of cases) 7
• Dizziness, sweating, nausea, vomiting, tremor, and somnolence 1

Critical Pitfalls to Avoid

• Do not underestimate delayed presentations—severe toxicity including seizures and cardiac arrest can occur many hours after ingestion 6, 4
• Do not assume single-agent SSRI overdoses are benign—citalopram specifically can cause severe serotonin syndrome and fatalities even without co-ingestants 6, 8
• Do not rely on standard pharmacokinetics—elimination half-life is significantly prolonged in overdose and does not correlate with ingested amount 7
• Consider pharmacogenetic factors (CYP2C19 intermediate or poor metabolizers) in patients with unexpectedly severe or prolonged toxicity 8

Supportive Care Measures

• Maintain electrolyte balance, particularly potassium and magnesium, as deficiencies can exacerbate QTc prolongation 5
• Provide general symptomatic and supportive care throughout hospitalization 1
• Contact poison control center for additional guidance on complex cases 1
• There are no specific antidotes for citalopram overdose 1