What is the treatment for Tricyclic Antidepressant (TCA) overdose?

From the Guidelines

Treatment for a tricyclic antidepressant (TCA) overdose should prioritize the use of sodium bicarbonate as the cornerstone of treatment, given as an IV bolus of 1-2 mEq/kg followed by continuous infusion to maintain blood pH between 7.45-7.55, as recommended by the 2023 American Heart Association guidelines 1.

Key Considerations

• The management of TCA overdose requires immediate medical attention in an emergency department, with a focus on reducing absorption and preventing cardiac arrhythmias.
• Sodium bicarbonate is recommended to treat life-threatening cardiotoxicity from TCA poisoning, with a Class of Recommendation (COR) of 1 and a Level of Evidence (LOE) of B-NR 1.
• The use of extracorporeal life support, such as VA-ECMO, may be considered for refractory cardiogenic shock from sodium channel blocker poisoning, with a COR of 2a and an LOE of C-LD 1.
• Lidocaine, a class Ib antidysrhythmic, may be used to treat wide-complex tachycardia from TCA overdose, with support from animal studies and human case reports 1.
• Intravenous lipid emulsion therapy may be considered in severe cases unresponsive to standard treatments, but its use is not recommended as first-line therapy 1.

Treatment Approach

• Initial management includes activated charcoal administration within 1-2 hours of ingestion to reduce absorption.
• Sodium bicarbonate is given as an IV bolus of 1-2 mEq/kg followed by continuous infusion to maintain blood pH between 7.45-7.55.
• Benzodiazepines like diazepam (5-10 mg IV) are used to control seizures.
• For severe cases with persistent hypotension, norepinephrine or epinephrine may be required.
• Cardiac monitoring is essential as TCAs can cause life-threatening arrhythmias.
• Intubation and mechanical ventilation may be necessary for respiratory depression.

Evidence-Based Recommendations

• The 2023 American Heart Association guidelines recommend the use of sodium bicarbonate to treat life-threatening cardiotoxicity from TCA poisoning 1.
• The guidelines also recommend considering the use of extracorporeal life support, such as VA-ECMO, for refractory cardiogenic shock from sodium channel blocker poisoning 1.
• The use of lidocaine and intravenous lipid emulsion therapy is supported by animal studies and human case reports, but their use is not recommended as first-line therapy 1.

From the Research

Treatment for TCA Overdose

• The treatment for TCA overdose is primarily supportive, with a focus on managing symptoms and preventing complications 2, 3, 4.
• Patients with suspected self-harm or malicious administration of a TCA should be referred to an emergency department immediately 2.
• Patients who are symptomatic after a TCA ingestion should be referred to an emergency department 2.
• Ingestion of a TCA in combination with other drugs may warrant referral to an emergency department 2.
• The ingestion of a TCA by a patient with significant underlying cardiovascular or neurological disease should cause referral to an emergency department at a lower dose than for other individuals 2.

Management of TCA Poisoning

• Sodium bicarbonate is considered the treatment of choice for severe TCA toxicity, although other supportive measures may be taken 3.
• Activated charcoal may be administered to patients with TCA poisoning, but its effectiveness is unknown 2, 5.
• Gastric lavage is not recommended for patients with TCA poisoning due to the risk of complications and lack of evidence for its effectiveness 5, 4.
• Haemoperfusion, haemodialysis, and the combination of these procedures are not recommended for patients with TCA poisoning due to the large volume of distribution of TCAs 5.

Cardiovascular and Neurological Management

• Cardiovascular toxicity is a common complication of TCA poisoning, and patients should be monitored for arrhythmias, hypotension, and other cardiac abnormalities 3, 4.
• Neurological symptoms such as seizures and coma may occur in patients with TCA poisoning, and patients should be monitored for these complications 3, 4.
• Benzodiazepines are recommended for the treatment of TCA-associated convulsions 2.
• Flumazenil is not recommended for patients with TCA poisoning 2.

Follow-up and Outcome

• Follow-up calls to determine the outcome for a TCA ingestion should be made within 4 hours of the initial call to a poison center and then at appropriate intervals thereafter based on the clinical judgment of the poison center staff 2.
• Patients who are asymptomatic after a TCA ingestion are unlikely to develop symptoms if the interval between the ingestion and the initial call to a poison center is greater than 6 hours 2.