A 58-year-old woman comes to the emergency department due to several hours of severe left-sided headache, nausea, and vomiting. She also has blurred vision and sees halos around lights. The patient has a history of hand tremors for which she recently started taking a new medication. She previously smoked, but does not use alcohol or illicit drugs. Temperature is 37 C (98.6 F), blood pressure is 150/90 mm Hg, and pulse is 96/min. The patient is in severe distress. Physical examination reveals left eye circum-corneal injection with a dilated and sluggish pupil. Visual acuity is decreased in the left eye. She has resting hand tremors and increased resistance to passive movements of the extremities. Which of the following medications is most likely causing her current symptoms?

Question

A 58-year-old woman comes to the emergency department due to several hours of severe left-sided headache, nausea, and vomiting.  She also has blurred vision and sees halos around lights.  The patient has a history of hand tremors for which she recently started taking a new medication.  She previously smoked, but does not use alcohol or illicit drugs.  Temperature is 37 C (98.6 F), blood pressure is 150/90 mm Hg, and pulse is 96/min.  The patient is in severe distress.  Physical examination reveals left eye circum-corneal injection with a dilated and sluggish pupil.  Visual acuity is decreased in the left eye.  She has resting hand tremors and increased resistance to passive movements of the extremities.  Which of the following medications is most likely causing her current symptoms?

Quizplus · Accepted Answer

11ec25c8_d5a5_9cb6_bc81_d5a97cdaf8ed_MD0003_00 This patient, with acute headache, nausea, blurry vision, and a sluggish/dilated pupil, has features of acute angle-closure glaucoma (ACG). Acute ACG is characterized by a sudden rise in intraocular pressure due to impaired drainage of aqueous humor through the pupil into the anterior chamber. Acute ACG can develop spontaneously or be triggered by certain medications (eg, decongestants, antiemetics, anticholinergics) in patients with predisposing anatomy. This patient's acute ACG was likely precipitated by trihexyphenidyl, an anticholinergic used in the treatment of symptomatic Parkinson disease (eg, resting tremor, cogwheel rigidity). Anticholinergic medications cause mydriasis, which may precipitate acute ACG. Untreated, acute ACG can damage the optic nerve and result in permanent vision loss within 2-5 hours of symptom onset. Urgent ophthalmologic consultation is required. (Choices A, B, and C) Entacapone increases dopamine stimulation and is often used in patients with Parkinson disease to potentiate the effects of levodopa/carbidopa. Both levodopa, a dopamine precursor, and pramipexole, a dopamine agonist, are commonly used in the initial treatment of symptomatic Parkinson disease. Dopamine stimulation does not typically increase the risk of ACG. Common side effects of these three medications include nausea, orthostatic hypotension, and dizziness. (Choice D) Propranolol is a beta blocker used to treat essential tremor, which is characterized by tremors that disturb goal-directed activities. No other neurologic manifestations (eg, rigidity) are usually present. Propranolol can cause bradycardia and hypotension but is unlikely to cause acute ACG. (Choice E) Selegiline is a monoamine oxidase type B inhibitor used in the treatment of Parkinson disease. Side effects include headache, dizziness, and nausea; selegiline is not typically associated with acute ACG. Educational objective: Acute angle-closure glaucoma (ACG) is a vision-threatening condition that may be associated with certain medications (eg, anticholinergics for Parkinson disease) or arise spontaneously. Manifestations include the sudden onset of severe eye pain, nausea, vomiting, unilateral conjunctival injection, and a dilated pupil with poor light response. Untreated, patients with acute ACG can develop permanent vision loss within 2-5 hours of symptom onset. Urgent ophthalmologic consultation is required. References: A review of drug-induced acute angle closure glaucoma for non-ophthalmologists. (http://www.ncbi.nlm.nih.gov/pubmed/26535174)

A 58-Year-Old Woman Comes to the Emergency Department Due to Several