What is the treatment for Selective Serotonin Reuptake Inhibitor (SSRI) poisoning?

Treatment of SSRI Poisoning

The treatment of SSRI poisoning requires immediate discontinuation of all serotonergic agents and hospital-based supportive care with continuous cardiac monitoring, as serotonin syndrome is the primary concern in these cases. 1

Clinical Manifestations

SSRI poisoning can present with a spectrum of symptoms ranging from mild to severe:

• Mild symptoms include nausea, vomiting, mydriasis, hypersalivation, and diaphoresis 2
• Moderate to severe symptoms indicate serotonin syndrome, characterized by:
  • Mental status changes (confusion, agitation, anxiety) 1
  • Neuromuscular hyperactivity (tremors, clonus, hyperreflexia, muscle rigidity) 1
  • Autonomic hyperactivity (hypertension, tachycardia, arrhythmias, tachypnea, diaphoresis, shivering, vomiting, diarrhea) 1
• Advanced symptoms include fever, seizures, arrhythmias, and unconsciousness, which can be fatal 1

Treatment Algorithm

1. Initial Management

• Discontinue all serotonergic agents immediately 1, 3
• Transport to emergency department for any patient with symptoms beyond mild effects 4
• Do not induce emesis 4

2. Hospital-Based Management

• Provide supportive care with continuous cardiac monitoring 1, 3
• For seizures: Administer intravenous benzodiazepines 4
• For hyperthermia (>104°F/40°C): Use benzodiazepines and external cooling measures 4
• Consider activated charcoal if presentation is within 1-2 hours of ingestion and the patient is alert with protected airway 4
• For serotonin syndrome:
  • Administer cyproheptadine (serotonin antagonist) 1, 5
  • Provide supportive care for autonomic instability 1

3. Cardiac Monitoring

• Monitor ECG, particularly with citalopram overdose, which has been associated with QT prolongation 6
• Citalopram may cause QT prolongation associated with Torsade de Pointes at doses exceeding 40 mg/day 1
• Other SSRIs have less risk of cardiac complications but should still be monitored 6

Special Considerations

• Drug-specific concerns:

  • Citalopram requires particular attention to cardiac monitoring due to significant QTc prolongation risk 6
  • Paroxetine, fluvoxamine, and sertraline have been associated with discontinuation syndrome 1

• Concomitant medications:

  • Avoid combining with MAOIs (phenelzine, isocarboxazid, moclobemide, isoniazid, linezolid) as this significantly increases serotonin syndrome risk 1
  • Exercise caution with other serotonergic drugs including opioids (tramadol, fentanyl), stimulants, cough/cold medications, and certain illicit drugs 1

Prognosis

• Most patients with SSRI overdose have excellent outcomes with appropriate supportive care 2, 7
• In one study, there were no deaths among 313 SSRI-poisoned dogs 2
• Mortality is rare but can occur with massive overdoses, particularly if presentation is delayed 5

Common Pitfalls to Avoid

• Failure to recognize serotonin syndrome, which can progress rapidly 1
• Administering additional serotonergic medications during treatment 1, 3
• Overlooking cardiac monitoring, especially with citalopram overdose 6
• Inadequate temperature monitoring and management in severe cases 1
• Relying solely on physical restraints for agitation, which can worsen hyperthermia 1