What is the treatment for an overdose of Prozac (fluoxetine)?

Management of Fluoxetine (Prozac) Overdose

Treatment of fluoxetine overdose requires immediate supportive care with airway management, cardiac monitoring, and gastric decontamination if performed soon after ingestion, while avoiding induction of emesis. 1

Initial Assessment and Stabilization

• Airway, Breathing, Circulation (ABC):

  • Ensure adequate airway, oxygenation, and ventilation
  • Monitor cardiac rhythm and vital signs continuously
  • Establish IV access

• Clinical Presentation:

  • Common symptoms: seizures, somnolence, nausea, tachycardia, vomiting
  • Severe cases: coma, delirium, ECG abnormalities (QT prolongation, ventricular tachycardia including torsades de pointes), hypotension, mania, pyrexia, stupor, syncope 1

Immediate Management

Gastric Decontamination

• Gastric lavage with large-bore orogastric tube may be indicated if performed soon after ingestion or in symptomatic patients
• Appropriate airway protection is essential if mental status is altered
• Do not induce emesis as this is not recommended 1

Cardiac Monitoring

• Continuous ECG monitoring is essential due to risk of QT prolongation and arrhythmias
• Monitor for torsades de pointes, especially with high doses 1, 2

Supportive Care

• Seizure Management:

  • Administer benzodiazepines for seizure control
  • Consider phenobarbital or propofol for refractory seizures

• Hemodynamic Support:

  • IV fluids for hypotension
  • Vasopressors may be required for persistent hypotension

• Temperature Management:

  • Active cooling measures for hyperthermia
  • Monitor core temperature in severe cases

Special Considerations

Serotonin Syndrome

• Monitor for mental status changes (confusion, agitation, anxiety), neuromuscular hyperactivity (tremors, clonus, hyperreflexia, muscle rigidity), and autonomic hyperactivity (hypertension, tachycardia, arrhythmias, tachypnea, diaphoresis) 2
• Treatment includes:
  • Discontinuation of all serotonergic agents
  • Supportive care with continuous cardiac monitoring
  • Benzodiazepines for agitation and tremor
  • Consider cyproheptadine in severe cases

Co-ingestions

• For suspected mixed overdoses:
  • If opioid co-ingestion suspected, administer naloxone first 3
  • If tricyclic antidepressant co-ingestion suspected, monitor ECG closely and treat accordingly
  • Avoid flumazenil in mixed overdoses, especially with tricyclic antidepressants 3

Monitoring and Disposition

• Monitor patients for at least 6 hours after ingestion
• Patients with significant symptoms require admission to an intensive care unit
• Extended monitoring (24+ hours) for patients with:
  • Significant ECG abnormalities
  • Persistent symptoms
  • Large ingestions (>1000 mg)
  • Presence of serotonin syndrome

Prognosis

• Most fluoxetine-only overdoses are relatively benign 4
• Among adult patients who overdosed on fluoxetine alone, approximately 60% completely recovered 1
• Fatal outcomes are rare with appropriate care, though ingestions as low as 520 mg have been associated with lethal outcomes (causality not established) 1

Important Cautions

• Avoid combining fluoxetine with MAOIs due to high risk of serotonin syndrome 2
• Fluoxetine's long half-life (1-3 days, up to 4 days with chronic use) and its active metabolite norfluoxetine (half-life of 7 days) may lead to prolonged symptoms 5
• Patients with hepatic or renal impairment may have delayed clearance and require extended monitoring

Remember that while most fluoxetine overdoses result in mild to moderate symptoms, severe toxicity can occur, particularly with large ingestions or when combined with other serotonergic medications.