Tca toxicity

this is about TCA toxicity

1. TCA TOXICITY Ehsan hasanpour 10/27/2018

2. Tricyclic antidepressant : They have been employed in drug therapy since the late 1950s. Largest group of drug agents used for the treatment of depression. Referred as “ tri cyclic ” compounds – three rings. Third most common cause of drug related death in US throughout 1980s

3. TCA Drugs : Secondary amines : - Amoxapine , Nortriptyline , Desipramine , Protriptyline . Tertiary amines :- Amitriptyline , Imipramine,Doxepin,Trimipramine . Tetra cyclic :- Maprotiline . Triazolopyridine :-Trazodone .

4. M echanism : Decreases the action of acetylcholine centrally and peripherally. Enhances dopamine levels. Reduced serotonin and norepinephrine uptake resultant increase within the synapse. Respiratory dysfunction and disturbances in body temp- respiratory center ,thermoregulatory site . Membrane-stabilizing effect on the myocardium by blocking the cardiac myocyte fast sodium channels

5. Bioavailability : slowly absorbed secondary to ionization in the stomach and slowing of peristalsis Can remain in gut for 12 hours or more Dissolve slowly 85-98% plasma bound

6. Cardiovascular manifestations of TCA Toxicity : Palpitation Chest pain Hypotension Ecg abnormality

7. CNS manifestations of TCA Toxicity : Convulsion Decrease mental status Respiratory depression Drowsiness Coma

8. Peripheral autonomic system manifestations : Dry mouth Dry skin Urinary retention constipation Blurred vision

9. Physical exam findings : Tachycardia Hypotension and orthostasis Fever Altered mental status Ileus Absent bowel sounds Rigidity Dry skin and mucous membranes Mydriasis

10. Electrolyte ( Na,K,Cl ,Ca) blood urea nitrogen (BUN), and creatinine levels Arterial blood gases (ABGs) for evaluation of acidosis or hypoxia Anion gap Complete blood cell count (CBC) Blood alcohol level Laboratory Studies :

11. Imaging Studies: Chest X Ray ECG:

12. Brugada Pattern :

13. Treatment : 25% of cases, patients were alert and awake at first prehospital contact Immediately evaluate the patient and administer oxygen. Monitor vital signs. Stabilization : Insert an intravenous line and cardiac monitoring. Altered mental status :naloxone , glucose and if indicated thiamine. Adequate ventilation ,prolonged cardiac massage. NO IPECAC (CNS depression can be rapid) Activated charcoal

14. SUPPORT VITAL FUNCTIONS: Respiratory depression : intubation and hyperventilation Hypotension : Nor epinephrine , Phenyl epinephrine, Sodium bicarbonate , Glucagon(10mg bolus followed by an infusion of 10 mg over 6 hours) . Dysrhythmias: sodium chloride, Sodium bicarbonate Convulsion : Diazepam(0.1 mg/kg iv ). Phenytoin infusion (15 mg/kg iv) over 30 min . Benzodiazepines ,Phenobarbital (15-20 mg/kg).