بنام خداوند بخشنده مهربان. tricyclic antidepressant poisoning tricyclic...

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  • TRICYCLIC ANTIDEPRESSANT POISONING

  • Tertiary Amines (tricyclic antidepressants)Amitriptyline ElavilDoxepin SinequanImipramine TofranilTrimipramine SurmontilAmoxapine AsendinMaprotiline LudiomilClomipramineSecondary Amines (tricyclic antidepressants)Nortriptyline (metabolite of amitriptyline) PamelorProtriptyline VivactilDesipramine (metabolite of imipramine) Norpramine

  • Dose > 1 g : Life treateningToxic dose: > 5 mg / kg Child : One pill can kill

  • 10-100 1% 90-95%

  • Overdose and ToxicityPatients presenting with a suspected TCA overdosed may exhibit no symptomatology or minor complications. Although the patients may appear well initially, they can rapidly and without warning develop life-threatening complications (hypotension, seizures, cardiac arrest)!! When in-hospital deterioration occurs, it is almost always within the first few hours after arrival and frequently within thefirst 60 minutes.

  • A.) Cardiovascular effects:

  • 1. Hypotension is the most frequent serious cardiovascular effect that occurs secondary to:a. Vasodilation form alpha1-adrenergic receptor blockade.b. Direct quinidine-like myocardial depressionc. Depletion of presynaptic norepinephrine stores Hypotension has been strongly correlated to the subsequent development of lifethreatening-ventricular arrhythmias.

  • 2. Sinus tachycardia lasting hours to days results from the anticholinergic toxicity. Supraventricular tachycardia (SVT) may occur secondary to anticholinergic toxicity. By itself, sinus tachycardia or SVT is usually not a serious complication in the setting of a TCA overdose.

  • Sinus Tachycardia

  • 3. Conduction delaysa. Widening of the QRS complex may result in unusual ECG patterns, and sinus tachycardia may be difficult to distinguish from ventricular tachycardia.b. Other ECG conduction abnormalities include prolonged PR and QTc interval, right axis shift, and high degree atrioventricular block.

  • Wide QRS (> 0.10 s)

  • 4. Arrhythmias include premature ventricular or atrial contractions, ventricular tachycardia,ventricular fibrillation, slow idioventricular rhythm, electromechanical dissociation, and asystole.When asystole occurs, hypotension and bradycardia usually precede it.

  • Ventricular Tachycardia

  • B.) CNS effects:

  • Altered mental status (Coma)

  • 1. Altered Mental Statusa. Delirium, agitation, and hallucinations may occur secondary to anticholinergic toxicity.b. Patient may have a level of consciousness ranging from mild sedation to coma.

  • 2. Myoclonus and choreoathetosis are relatively benign muscle contractions that are sometimesmistaken for prolonged seizures.

  • Seizure

  • 3. Seizuresa. Prior mental status does not predict the occurrence of seizuresb. Usually brief and self-limited.c. Prolonged seizures do occur, and resulting acidosis and hypoxia may potentiate cardiotoxicity.d. Amoxapine and maprotiline appear to have a relatively greater seizure potential.

  • C.) Anticholinergic effects:

  • Peripheral autonomic nervous system complications are common and by themselves do not cause significant morbidity. Centrally mediated anticholinergic effects are a more serious complication (see CNS effects) requiring close monitoring and supportive care. The presence or absence of anticholinergic symptoms does not predict more serious complications.

  • Management of TCA PoisoningABCD; AntidoteEmesis (Ipecac ?)Gastric Lavage Activated Charcoal: 1 g/kg, 50-100 gMultiple Dose Activated CharcoalCathartic : Sorbitol 70%, 1-2 cc / kg

  • From TRIPP, CPEMA:Airway compromise B: Breathing difficulties

  • C : CirculationBlood pressurePulse (rate; regularity)IV line; ECGManage hypotensionManage Dysrhythmia

  • Antidote: Sodium BicarbonateSevere toxicity : HypotensionComaSeizures Arrythmia Wide QRS > 0.1 s R avR 3 mm Dose: 1-2 mEq/kg bolus, rebolus prn to maintain a desired arterial pH of 7.5. Sodium bicarbonate infusion is usually required to maintain a desired pH of 7.45-7.55.Dose: 100-150 mEq NaHCO3 per liter in D5W 1/2 NS at 150-200 cc/hr (rates should be adjusted per patient)

  • Antidote: Sodium BicarbonateNot Severe toxicity

    Infusion (50-150 mEq / L D5W)

  • C.) Hypotension1. Trendelenburg position, IV fluids, and sodium bicarbonate.2. Norepinephrine is the drug of first choice as it is a potent selective alpha-adrenergic receptor agonist. TCAs are selective alpha-adrenergic blockers. ( requires IV placement of central line)Dose: 0.1-0.2 mcg/kg/min initially and then titrate to effect.3. Dobutamine may be used if the hypotension is due to a loss of inotropy where the cardiac output is low and the pulmonary artery wedge pressure is > 18 mm Hg.Dose: 2.5 mcg/kg/min initially titrated up to 15 mcg/kg/min4. Dopamine use in managing the TCA poisoned patient is falling out of favor. Dopamine needs to be converted to norepinephrine for in order to achieve positive alpha-adrenergic stimulation in vivo. Overdoses involving TCAs as well as cocaine and amphetamines cause catecholamine depletion making dopamine less effective when managing hypotension in these cases.

  • Ventricular Tachycardia Unstable VT: Basic + ACLSStable VT: NaHCO3: 1-2 mEq / kg, IVLidocaine: 1.5 mg / kg, Total: 3 mg /kg Infusion: 2-4 mg/minMg SO4 : 1-2 g IV slowOverdrive Pacing

  • ConvulsionsOxygen, airway, IV Line; NaHCO3Diazepam: Adult: 5-10 mg IV ( Total 30 mg)Child: 0.1-0.3 mg / kgConsider ventilation ( intubation, ABG)Phenytoine (-)Phenobarbital: 10 mg / kg IVSodium Thiopental: 3- 5 (15 mg / kg), infusion 1-5mg / kg/ h (Hypotension, Res. Depression)Midazolam : 0.1-0.3 mg/kg boluse , Infusion

  • ContraindicationPhenytoinAntiarrhythmic Drugs: Type 1a , 1c (Procainamide,)PropranololFlumazenil

  • SummaryIntubation; Oxygen; (Glucose, Naloxone)IV line; ECG; ABG; Urine cathetherSodium bicarbonate 1-2 mEq/kg boluseSerum (1/3 2/3) 1L / 8h+ 50 mEq NaHCO3

  • E. mail:gheshlaghi@med.mui.ac.ir

  • Management of TCA Poisoning 1- A B C D(Antidote)

  • ;

  • Midriasis

  • Sinus Tachycardia

  • HypertermiaDry skin and mucous membranesUrinary RetentionIleus

  • Sinus Tachycardia

  • Hypotension

  • DeliriumHallocination

  • HypotensionFluids : N.S, Lactated Ringer Adult: 500-1000 cc Children: 10-20 cc / kgSodium Bicarbonate : 1-2 meq/kgNorepinephrine : 0.1-0.5 g/kg/min Dopamine : 10-20 g / kg / min

  • Tricyclic AntidepressantsSymptoms

    1- Midriasis ; Tachycardia 2- Coma 3- Delirium 4- Seizures 5- Hypotension QRS > 0.1s ; R avR >= 3 mm ; Right Axis deviation ; Arrhythmias (VT); First A-V block

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