Which of the following is incorrect about tricyclic antidepressants overdose?
A. GI decontamination for severely ill patients should consist of gastric lavage followed by the administration of activated charcoal, and, preferably, the patient has to pass a charcoal stool. Because some cyclic antidepressants have a small enterohepatic circulation, an additional one to two doses of aqueous charcoal (25 g) can be considered every 4 hours until the patient awakens
B. Hemodialysis and hemoperfusion are not effective in reducing the toxic effects of cyclic antidepressants
C. Alkalinization for abnormal cardiac conduction (QRS complex greater than 100 milliseconds in the limb leads, and ventricular dysrhythmias) also helps to control seizure activity.
D. Diuresis of an alkaline urine is not necessary for the beneficial effect of alkalinization for abnormal cardiac conduction.
Answer: C
Alkalinization for abnormal cardiac conduction does not affect seizure activity. For alkalinization, a combination of sodium bicarbonate infusion and hyperventilation may be more useful than either alone. By combining the two modalities, the arterial partial pressure of carbon dioxide can be maintained at 30 to 34 mm Hg, which prevents cerebral vasoconstriction, while serum sodium is kept within reasonable limits. Optimal arterial pH is between 7.45 and 7.55.