I appreciated “The psychotic pot smoker” (Cases that Test Your Skills, Current Psychiatry, September 2010, p. 42-47). There were few pointers that suggested looking for benzodiazepine or alcohol withdrawal, especially because the authors lacked a reliable history from the patient. They mentioned that the patient had mild tachycardia (101 bpm), elevated blood pressure (149/57 mm Hg), orientation to name (and I assume disoriented to place and time), and hyperreflexia (due to GABA effect).
One differential diagnosis was missing: delirium. I did not read about cognitive testing in this patient with a differential diagnosis of delirium; maybe a clock test would have done some good.
I would have approached this case as delirium and then proceeded with lab and imaging tests. Elevated white blood cell count and creatine phosphokinase test were distractors (lumbar puncture and electroencephalography can be justified). How would you justify giving diphenhydramine to a patient with delirium, considering that it might worsen confusion or agitation?
I agree, however, that this case was complex and can’t help but emphasize that benzodiazepine or alcohol withdrawal is a simple condition that can be life-threatening if missed.
Ghazanfar Khan, MD
University of Mississippi Medical Center