Management of SSRI Poisoning
For suspected SSRI poisoning, prioritize supportive care with airway management and benzodiazepines for seizures or severe agitation, while monitoring for serotonin syndrome—most patients can be safely observed at home if asymptomatic after ingesting less than 5 times a single therapeutic dose without suicidal intent. 1
Immediate Assessment and Triage
Contact a poison control center immediately for expert guidance, as timely consultation with medical toxicologists facilitates rapid and effective therapy. 2
Risk Stratification for Emergency Department Referral
All patients with suicidal intent, intentional abuse, or suspected malicious intent (e.g., child abuse) must be referred to an emergency department regardless of dose reported. 1
Any patient experiencing symptoms beyond mild effects (anything more than vomiting, light somnolence, mydriasis, or diaphoresis) should be transported to an emergency department. 1
Asymptomatic patients or those with only mild effects following unintentional acute ingestions of up to 5 times an initial adult therapeutic dose can be observed at home: 1
- Citalopram: ≤100 mg
- Escitalopram: ≤50 mg
- Fluoxetine: ≤100 mg
- Fluvoxamine: ≤250 mg
- Paroxetine: ≤100 mg
- Sertraline: ≤250 mg
For patients already taking an SSRI chronically, ingestions up to 5 times their own single therapeutic dose can be observed at home with poison center follow-up. 1
Life-Threatening Complications: Immediate Interventions
Secure airway, breathing, and circulation as the first priority, following standard advanced life support principles. 2, 3
Serotonin Syndrome Management
Serotonin syndrome occurs in 14-16% of SSRI overdoses and manifests as tremor, diarrhea, delirium, neuromuscular rigidity, and hyperthermia. 2, 4
Administer intravenous benzodiazepines (diazepam or midazolam) for seizures or severe agitation. 3, 1
For hyperthermia >104°F (>40°C), use benzodiazepines combined with external cooling measures. 1
Neuromuscular rigidity and autonomic instability indicate severe serotonin syndrome requiring immediate ICU-level care. 5
Decontamination Strategies
Do not induce emesis under any circumstances. 1
The routine use of out-of-hospital activated charcoal in patients with unintentional SSRI overdose cannot be advocated, as there are no data suggesting specific clinical benefit. 1 However, activated charcoal can be considered if the patient is fully conscious and capable of swallowing safely, preferably within 2 hours of ingestion. 6
Monitoring Requirements
Follow-up calls should be made during the first 8 hours after ingestion for home-observed patients. 1
Consider emergency department referral if observation would occur during normal sleeping hours of the patient or caretaker, as this may not reliably identify onset of toxicity. 1
Patients should be observed for at least 6 hours post-ingestion; asymptomatic patients beyond 6 hours are unlikely to develop symptoms. 1, 7
Cardiac Considerations: Citalopram-Specific Risk
Citalopram carries significantly increased risk of QTc prolongation compared to other SSRIs, with 68% of overdoses showing QTc >440 msec. 4
Cardiac monitoring should be strongly considered in citalopram overdose, particularly with large ingestions or in patients with underlying cardiac disease. 4
The median QTc for citalopram overdose is 450 msec (IQR: 436-484), significantly higher than fluoxetine, fluvoxamine, paroxetine, and sertraline. 4
Overall Prognosis and Safety Profile
SSRIs are relatively safe in overdose despite the common occurrence of serotonin syndrome. 4 In one retrospective study of 313 SSRI-poisoned dogs, there were no deaths, and this favorable safety profile extends to human exposures. 5
The ICU admission rate for SSRI overdose is approximately 6.4%, with seizure incidence of 1.9% and coma incidence of 2.4%. 4
Median length of stay for SSRI overdose admissions is 15.3 hours (IQR: 10.5-21.3). 4
Critical Pitfalls to Avoid
Do not delay treatment while waiting for confirmatory testing—treat based on clinical presentation and history of exposure. 8, 9
Be aware that combining SSRIs with other serotonergic medications (including tramadol, fentanyl, mirtazapine, buspirone, amitraz, and chlorpheniramine) significantly increases risk of serotonin syndrome. 2, 5
Consider observation during waking hours only, as sleeping caregivers may miss early signs of deterioration. 1
Transportation via ambulance should be considered based on patient condition and anticipated time to reach the emergency department. 1