From the Guidelines
The female patient who has ingested 10 tablets of amitriptyline along with rat poison requires immediate emergency medical attention, and treatment should include sodium bicarbonate IV to counteract the cardiac toxicity from the tricyclic antidepressant overdose, as well as vitamin K1 administration to address the anticoagulant effects of the rodenticide. The patient's condition is life-threatening and necessitates hospital care. At the hospital, treatment will likely include gastric decontamination with activated charcoal if the ingestion was recent (within 1-2 hours) [ 1 ]. For the tricyclic antidepressant overdose, sodium bicarbonate IV (1-2 mEq/kg) will be administered to treat cardiac toxicity, along with continuous cardiac monitoring, as recommended by the 2023 American Heart Association guidelines [ 1 ].
Key Treatment Components
- Sodium bicarbonate IV to treat cardiac toxicity from tricyclic antidepressant overdose
- Vitamin K1 (phytonadione) administration to counteract anticoagulant effects of rodenticide
- Gastric decontamination with activated charcoal if ingestion was recent
- Continuous cardiac monitoring
- Benzodiazepines for seizure management if necessary
- Supportive care including IV fluids, respiratory support, and treatment of arrhythmias as needed
The combination of these toxins is particularly dangerous, as tricyclics can cause cardiac arrhythmias, seizures, and coma, while anticoagulant rodenticides prevent blood clotting, potentially causing internal bleeding [ 1 ]. The long half-life of many rodenticides means treatment may need to continue for weeks. It is crucial to follow the guidelines for the management of patients with cardiac arrest or life-threatening toxicity due to poisoning, as outlined in the 2023 American Heart Association focused update [ 1 ].
From the FDA Drug Label
- Overdosage Deaths may occur from overdosage with this class of drugs. Multiple drug ingestion (including alcohol) is common in deliberate tricyclic antidepressant overdose. As the management is complex and changing, it is recommended that the physician contact a poison control center for current information on treatment Signs and symptoms of toxicity develop rapidly after tricyclic antidepressant overdose, therefore, hospital monitoring is required as soon as possible. Other signs of overdose may include: impaired myocardial contractility, confusion, disturbed concentration, transient visual hallucinations, dilated pupils, disorders of ocular motility, agitation, hyperactive reflexes polyradiculoneuropathy, stupor, drowsiness, muscle rigidity, vomiting, hypothermia, hyperpyrexia, or any of the symptoms listed under ADVERSE REACTIONS Management General Obtain an ECG and immediately initiate cardiac monitoring. Protect the patient’s airway, establish an intravenous line and initiate gastric decontamination. Gastrointestinal Decontamination All patients suspected of tricyclic antidepressant overdose should receive gastrointestinal decontamination. This should include, large volume gastric lavage followed by activated charcoal.
The treatment for a female who has ingested 10 tablets of amitriptyline along with rat poison includes:
- Immediate hospital monitoring as soon as possible
- Gastrointestinal decontamination with large volume gastric lavage followed by activated charcoal
- Cardiac monitoring with an ECG
- Protection of the patient's airway and establishment of an intravenous line
- Contacting a poison control center for current information on treatment Regarding the pupils, dilated pupils are a possible sign of overdose. 2
From the Research
Treatment for Amitriptyline and Rat Poison Ingestion
- The treatment for a female who has ingested 10 tablets of amitriptyline (tricyclic antidepressant) along with rat poison (anticoagulant) involves addressing both the cardiotoxic effects of amitriptyline and the anticoagulant effects of the rat poison.
- For amitriptyline toxicity, primary treatment strategies include sodium bicarbonate, hypertonic saline, and correction of any conditions that may aggravate this toxicity such as acidosis, hyperthermia, and hypotension 3.
- In cases of severe TCA toxicity, administration of sodium bicarbonate may be insufficient to correct the cardiac conduction defects, and the use of lidocaine or phenytoin, both Vaughan Williams Class IB antiarrhythmic agents, has been reported as an effective adjunctive therapy 3.
- Activated charcoal can be used to prevent the absorption of amitriptyline, and its effectiveness can be increased by administering it in repeated doses 4.
- The adsorption of amitriptyline to activated charcoal can be affected by the presence of other drugs, such as paracetamol, but activated charcoal still has a high adsorptive capacity for both drugs 5.
Management of Pupils
- There is no direct information on the management of pupils in the context of amitriptyline and rat poison ingestion.
- However, in general, the management of patients with severe traumatic brain injury, which may be a potential consequence of such ingestion, involves preventing secondary brain injuries by maintaining adequate oxygenation, blood pressure, and ventilation 6.
- The use of medications such as ketamine and benzodiazepines for intubation, and mannitol or hypertonic saline to decrease intracranial pressure, may be considered in the management of patients with severe traumatic brain injury 6.