Master the board step 3

Psychiatry
An elderly patient presents with depression and agitation. What is the most
appropriate medication?
Answer: Give an antidepressant with sedative effects (e.g., doxepin, trazodone).
Amitriptyline is also sedating but has anticholinergic effects, which may be problematic
in elderly.
A 25-year-old male with history of seizures is diagnosed with depression. Which
medications should be avoided?
Answer: Seizures are common with TCAs and bupropion, and these medications
should be avoided in patients with seizure disorders. The best first-line therapy in
patients with seizures is SSRIs.
A middle-aged woman is brought into the ER with confusion and disorientation.
An overdose of prescription medications is suspected. Blood pressure is 90/53 mm
Hg, HR 111/min. Pupils are dilated, mucous membranes are dry, and she has facial
flushing.
1. What is the most likely cause of acute intoxication?
2. What is the most important test to determine severity and prognosis in this
patient?
a. EKG
b. EEG
c. Serum sodium
d. Serum tricyclic levels
e. Urinalysis
3. EKG is performed and shows PR and QRS prolongation and sinus tachycardia.
What is the most appropriate next step in management?
a. Calcium carbonate
b. Diazepam
c. Gastric lavage
d. Insulin and glucose
e. Sodium bicarbonate
Answers:
1. Tricyclic antidepressants (TCAs): TCAs have anticholinergic effects and are an
alpha blocker, causing peripheral vasodilatation and hypotension and also affecting
sodium channels in cardiac tissue.
2. A. EKG is the single most important test to guide therapy and prognosis. Watch out
for prolonged QRS, QT, and PR intervals. Most serious complication is ventricular
tachycardia and fibrillation.
3. E. Sodium bicarbonate attenuates TCA cardiotoxicity by alkalinization of blood, which
uncouples TCA from myocardial sodium channels and increases extracellular sodium
concentration, thereby improving the gradient across the channel.
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