Nortrilen Overdosage

There is considerably individual variability in response to overdose.
Children are especially susceptible to cardiotoxicity and seizures.
In adults more than 500 mg have caused moderate to serious intoxication and less than 1000 mg have been fatal.
Symptoms: The symptoms can occur slowly and insidious or abruptly and surprisingly. During the first hours somnolence or excitation, agitation and hallucinations.
Anticholinergic symptoms: Mydriasis, tachycardia, urinary retention, dry mucous membranes, reduced bowel motility. Convulsions. Fever. Sudden occurrence of CNS depression. Lowered consciousness progressing into coma. Respiratory depression.
Cardiac symptoms: Arrhythmias (ventricular tachyarrhythmias, torsade de pointes, ventricular fibrillation). The ECG characteristically show prolonged PR interval, widening of the QRS-complex, QT prolongation, T-wave flattening or inversion, ST segment depression, and varying degrees of heart block progressing to cardiac standstill. Widening of the QRS-complex usually correlates well with the severity of the toxicity following acute overdoses. Heart failure, hypotension, cardiogenic shock. Metabolic acidosis, hypokalemia.
During awakening possibly again confusion, agitation and hallucinations and ataxia.
Treatment: Patients should be admitted to hospital (intensive care unit) and closely monitored even in apparently uncomplicated cases. The treatment is symptomatic and supportive.
ABC's (airway, breathing and circulation) should be assessed and treated as appropriate. Patency of the airway is maintained by intubation, where required. Treatment in a respirator is advised to prevent a possible respiratory arrest. Continuous ECG-monitoring of cardiac function for 3-5 days is advised. Urea and electrolytes should be checked, in particular for low potassium. Urine output should be monitored. Arterial blood gases should be checked, in particular for acidosis. Consider gastric lavage only if within one hour of a potentially fatal overdose. Give 50 g of charcoal if within one hour of ingestion.
Treatment of the following will be decided on a case by case basis: Wide QRS-intervals, cardiac failure and ventricular arrhythmias; Circulatory failure; Hypotension; Hyperthermia; Convulsions; Metabolic acidosis.
Unrest and convulsions may be treated with diazepam.
Patients who display signs of toxicity should be monitored for a minimum of 12 hours. Monitor for rhabdomyolysis if the patient has been unconscious for a considerable time. Since overdosage is often deliberate, patients may attempt suicide by other means during the recovery phase. Deaths by deliberate or accidental overdosage have occurred with this class of medicament.