A 32-year-old woman is brought to the emergency department by her husband due to slurred speech and difficulty walking. The patient has also been uncharacteristically drowsy for the past several hours. She has a history of bipolar disorder, insomnia, migraine headaches, seizures, and hypothyroidism. Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, pulse is 76/min, and respirations are 12/min. The patient is lethargic and falls asleep during the interview and physical examination. Pupils are 3 mm and reactive to light. The neck is supple and the oropharynx is clear. Chest auscultation is unremarkable. The abdomen is soft and nontender; bowel sounds are normal. Limited neurologic examination shows 2+ deep tendon reflexes in all 4 extremities; there is no Babinski sign and strength is 5 on a scale of 0-5 throughout. No nystagmus or hand tremor is present. Blood glucose is 130 mg/dL. Which of the following is the most likely cause of this patient's symptoms?

Question

A 32-year-old woman is brought to the emergency department by her husband due to slurred speech and difficulty walking.  The patient has also been uncharacteristically drowsy for the past several hours.  She has a history of bipolar disorder, insomnia, migraine headaches, seizures, and hypothyroidism.  Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, pulse is 76/min, and respirations are 12/min.  The patient is lethargic and falls asleep during the interview and physical examination.  Pupils are 3 mm and reactive to light.  The neck is supple and the oropharynx is clear.  Chest auscultation is unremarkable.  The abdomen is soft and nontender; bowel sounds are normal.  Limited neurologic examination shows 2+ deep tendon reflexes in all 4 extremities; there is no Babinski sign and strength is 5 on a scale of 0-5 throughout.  No nystagmus or hand tremor is present.  Blood glucose is 130 mg/dL.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

This patient's slurred speech, unsteady gait, and drowsiness are consistent with a benzodiazepine overdose. Benzodiazepines are used for the treatment of anxiety, insomnia, and seizures and for alcohol withdrawal. In the absence of coingestion, benzodiazepine intoxication typically presents with normal vital signs and pupillary size (2-4 mm in bright light). Respiratory depression may develop when coingestion (eg, opioids, alcohol) has occurred or when benzodiazepines are administered intravenously. (Choice B) Lithium toxicity presents with tremor, hyperreflexia, ataxia, seizures, vomiting, and diarrhea. (Choice C) In addition to sedation, opioid intoxication presents with respiratory depression and miosis. (Choice D) Phenytoin toxicity presents with horizontal nystagmus, cerebellar ataxia, and confusion. (Choice E) Serotonin syndrome presents with hypertension, tachycardia, hyperreflexia, clonus, and agitation in the setting of serotonergic drug use (eg, coprescription of antidepressant and triptan). This patient's slurred speech and overall presentation is better explained by benzodiazepine overdose. Educational objective: Slurred speech, unsteady gait, and drowsiness can be seen in the overdose of multiple drugs. Benzodiazepine overdose can be distinguished from opioid overdose by the lack of severe respiratory depression and the lack of pupillary constriction. References: Serial monitoring of sedation scores in benzodiazepine overdose. (http://www.ncbi.nlm.nih.gov/pubmed/24908447)

A 32-Year-Old Woman Is Brought to the Emergency Department by Her