A 35-year-old patient enters the ED and loudly proclaims he took 50 imipramine tablets approximately an hour ago. Physical examination reveals an alert and oriented thin patient in no apparent distress. His heart rate is 110/min, blood pressure is 120/60 mm Hg, and his pupils are dilated but reactive. The remainder of his examination is normal. In managing this patient, you should know:
He should immediately receive oral syrup of ipecac, be placed on a cardiac monitor, and have an intravenous line established.
+Less than 5% of patients who die of antidepressant overdose are awake and alert at the time of first medical contact.
+A short QT interval with a normal QRS duration and nonspecific ST-T wave changes should be expected on the EKG.
+The amount of drug ingested is clinically irrelevant in initially managing the treatment.
+Arterial blood gases should be drawn at the first sign of cardiovascular toxicity.
Twenty-five percent of fatal antidepressant overdoses are in people who are awake at the time of initial presentation. The amount taken is not useful in predicting the clinical outcome or guiding the initial management of overdose because of differences in sensitivity between patients. Gastric lavage should not be used for decontamination because of the risk of rapid deterioration. Ipecac delays the use of activated charcoal. Cardiovascular complications are dependent on pH. ABG measurements are indicated with any CNS changes, and blood pH should be kept above 7.4. Tachycardia, prolonged QRS duration, and conduction abnormalities are common, but death is often the result of profound myocardial depression.