https://padlet.com/aagouni78/javntmlsdq2d Made with a taste for adventure en-us 2017-11-23 08:03:10 UTC 2026-01-21 20:31:33 UTC hello@padlet.com https://padlet.com/aagouni78/javntmlsdq2d/wish/404877329 1) What are the primary mechanisms of toxicity in TCA overdose?
Inhibits re-uptake of catecholamines which results in tachycardia and hypertension. 
They also depress the myocardial membrane through a quinidine
like effect hence causes cardiac conduction abnormalities and inhibits the fast sodium channels and initiates cardiac cell action potential. 


2) Describe the three major clinical features of TCA overdose.
Sedation, sinus tachycardia, hypotension caused by venodilation. Seizures can also occur accompanied with hyperthermia 

3) Explain why patients with TCA overdose who often appear awake may abruptly lose consciousness or develop seizures without warning.
TCAs through anti-cholinergic blockade slows it's own gastric emptying time and slows down its absorption hence why symptoms begin within 30 to 40 mins of ingestion 

4) What ECG findings are typical of TCA overdose?
Sinus tachycardia with PR, QRS and QT prolongation. 

5) Why the plasma levels of TCAs are not used in the emergency
management of TCA poisoning?
QRS prolongation and clinical manifestations are more reliable indicator of toxicity and are more readily available

6) Which laboratory tests are useful to diagnose TCA overdose?
ECG, arterial blood gas, can be expressed in urine. 

7) What is the specific antidote for TCA overdose?
Sodium Bicarbonate

8) What are the possible mechanisms of therapeutic effect of sodium
bicarbonate in TCA overdose?
Increases the intracellular sodium concentrations and hence it will reverse the membrane depressant effect. It also has a direct effect on pH which influence the fast sodium channel. 

9) Physostigmine, (an anticholinesterase inhibitor), is routinely used in the
clinic to reverse anticholinergic effects. However, the use of
Physostigmine during TCA overdose is strongly discouraged despite
the toxicity caused by anticholinergic effects of TCAs. Why?
It may aggravate the conduction abnormalities causing asystole and further impairing the myocardial contractility. 

10)Explain the emergency and supportive measures to treat TCA overdose.
Maintain ABC Treat coma, seizures, hyperthermia, hypotension, arrythmias Consider overdrive pacing for bradyarrythmias and AV block; use overdrive pacing for torsades de Pointes Mechanical support of circulation for refractory shock NM blockers for refractory seizures to prevent hyperthermia Monitor vitals and ECG

11) Which methods of decontamination are useful in TCA overdose?
Activated charcoal; gastric lavage for ONLY large doses (>20-30 mg/kg)

12) Why the routinely used methods to enhance elimination of poisons
such as hemodialysis and hemoperfusion are ineffective to treat TCA overdosed patient?
Because the drug is highly distributed and highly protein bound]]> 2019-10-31 08:22:24 UTC https://padlet.com/aagouni78/javntmlsdq2d/wish/404877329