What is the management for a clonidine (antihypertensive) and sertraline (selective serotonin reuptake inhibitor) overdose?

Management of Clonidine and Sertraline Overdose

Immediate supportive care with airway protection, cardiac monitoring, and treatment of specific physiologic abnormalities (bradycardia, hypotension, CNS depression) is the cornerstone of management for combined clonidine and sertraline overdose, as there are no specific antidotes for either drug. 1, 2

Initial Assessment and Stabilization

Airway and Breathing

• Ensure adequate airway, oxygenation, and ventilation immediately, as clonidine overdose can cause respiratory depression and apnea within 30 minutes to 2 hours of ingestion 2, 3
• Intubation may be necessary for severe CNS depression (GCS <9), though this is more common with co-ingestants 4
• Monitor closely for apnea and respiratory depression, which occur more frequently in children than adults 3

Gastrointestinal Decontamination

• Administer activated charcoal if the patient presents within 1-2 hours of ingestion and can protect their airway 1
• Do NOT induce vomiting with ipecac, as clonidine overdose causes rapid CNS depression 2
• Gastric lavage with a large-bore orogastric tube may be indicated only if performed soon after ingestion in symptomatic patients with appropriate airway protection 1, 2

Cardiovascular Management

Bradycardia

• Atropine sulfate is the first-line treatment for hemodynamically significant bradycardia, effectively correcting heart rate in clonidine overdose 2, 3, 5
• Expect bradycardia to persist for a median of 20 hours (range 2.5-83 hours), with onset typically 2.5 hours post-ingestion 4
• Monitor for bradycardia even with doses as low as 0.1 mg in children 2

Hypotension

• Treat hypotension with intravenous fluid resuscitation first, followed by dopamine infusion if volume expansion is inadequate 2, 3, 5
• Vasopressor agents may be necessary for refractory hypotension 2
• Note that hypotension typically follows an initial hypertensive phase in massive overdoses 2, 6

Hypertension

• Early hypertension may occur with massive clonidine ingestions (>8,000 μg) due to peripheral alpha-agonist effects 4, 5
• If hypertension is severe and sustained, consider vasodilators such as sodium nitroprusside 2, 6
• Hypertension is typically transient and followed by hypotension 2, 5

Central Nervous System Effects

CNS Depression

• Expect CNS depression in approximately 68% of cases, with miosis occurring in 29% (mimicking opioid overdose) 4
• Monitor Glasgow Coma Score closely, as decreased or absent reflexes, drowsiness, and weakness are common 2
• Seizures, coma, hallucinations, and delirium can occur with large overdoses 2, 5

Naloxone Consideration

• Naloxone may be useful as a diagnostic and therapeutic adjunct for clonidine-induced respiratory depression, hypotension, and coma, though evidence of efficacy is limited 2, 3
• Typical dose is 2 mg (range 1.2-2.4 mg), but only partial improvement in GCS has been documented 4
• Monitor blood pressure carefully during naloxone administration, as paradoxical hypertension can occur 2

Sertraline-Specific Considerations

Expected Clinical Effects

• The most common signs of sertraline overdose are somnolence, vomiting, tachycardia, nausea, dizziness, agitation, and tremor 1
• Serious complications include serotonin syndrome, QT-interval prolongation, Torsade de Pointes, seizures, and cardiac conduction abnormalities 1
• Deaths have occurred with sertraline overdose, though the margin of safety is greater than with other antidepressants 7, 1

Serotonin Syndrome Monitoring

• Monitor for serotonin syndrome, which presents with mental status changes (confusion, agitation), neuromuscular hyperactivity (tremors, clonus, hyperreflexia, muscle rigidity), and autonomic hyperactivity (hypertension, tachycardia, diaphoresis) 7
• Advanced symptoms include fever, seizures, arrhythmias, and unconsciousness that can be fatal 7
• Treatment requires discontinuation of all serotonergic agents and supportive care with continuous cardiac monitoring 7

Continuous Monitoring Requirements

• Maintain continuous cardiac rhythm monitoring and vital sign assessment throughout hospitalization 7, 1
• Expect median length of stay of 21 hours (range 14-35 hours) for clonidine overdose 4
• Monitor for cardiac conduction defects, dysrhythmias, bradycardia, bundle branch block, and QT prolongation 1, 2
• Assess for hypothermia, which can occur with clonidine overdose 2

Ineffective Treatments to Avoid

• Tolazoline is NOT recommended, as it has yielded inconsistent results and was found ineffective in reversing clonidine overdose symptoms 2, 3, 5
• Forced diuresis, dialysis, hemoperfusion, and exchange transfusion are unlikely to benefit sertraline overdose due to large volume of distribution 1
• Dialysis is not likely to significantly enhance clonidine elimination 2

Critical Pitfalls

• Do not underestimate toxicity in children, as little as 0.1 mg of clonidine has produced signs of toxicity, and CNS depression frequency is higher in pediatric patients 2, 3
• Be aware that clonidine overdose can present with a biphasic response: initial hypertension followed by hypotension 2, 4, 5
• Consider multiple drug involvement when managing overdose, as co-ingestants increase the risk of severe CNS depression requiring intubation 1, 4
• Monitor for paralytic ileus, which can occur with massive clonidine overdose 8