A 78-year-old healthy, Chinese-American man is brought to the emergency department because of hallucinations, delusions, and aggressive behavior, according to his nephew. He has had these symptoms for the past six days. He denies fever, chills, decreased vision, headaches, or abdominal pain. His other medical problems include hypertension, coronary artery disease, and osteoporosis. He does not use tobacco or drink alcohol. He is a vegan. He lives alone. His medications include aspirin, hydrochlorothiazide, enalapril, acetaminophen, and diclofenac. He has no known drug allergies. His blood pressure is 141/88 mmHg, pulse is 100/min, temperature is 37.2 C (99 F), and respirations are 14/min. Examination shows dry mucus membranes and a loud second heart sound. The abdomen is soft, nontender, and non-distended. Bowel sounds are mildly increased. There is no rebound tenderness or rigidity. The range of motion of the spine is normal and without pain. There is no scoliosis or excessive kyphosis of the back. There is no tenderness to palpation of the lower back. The mental status examination reveals an agitated, elderly man with delusional ideation and bizarre behavior. There are no motor or sensory focal deficits, and no meningeal signs. The patient's labs reveal: His chest-x ray and urinalysis results are normal. Which of the following is the most appropriate pharmacotherapy?

Question

A 78-year-old healthy, Chinese-American man is brought to the emergency department because of hallucinations, delusions, and aggressive behavior, according to his nephew.  He has had these symptoms for the past six days.  He denies fever, chills, decreased vision, headaches, or abdominal pain.  His other medical problems include hypertension, coronary artery disease, and osteoporosis.  He does not use tobacco or drink alcohol.  He is a vegan.  He lives alone.  His medications include aspirin, hydrochlorothiazide, enalapril, acetaminophen, and diclofenac.  He has no known drug allergies.  His blood pressure is 141/88 mmHg, pulse is 100/min, temperature is 37.2 C (99 F), and respirations are 14/min.  Examination shows dry mucus membranes and a loud second heart sound.  The abdomen is soft, nontender, and non-distended.  Bowel sounds are mildly increased.  There is no rebound tenderness or rigidity.  The range of motion of the spine is normal and without pain.  There is no scoliosis or excessive kyphosis of the back.  There is no tenderness to palpation of the lower back.  The mental status examination reveals an agitated, elderly man with delusional ideation and bizarre behavior.  There are no motor or sensory focal deficits, and no meningeal signs.  The patient's labs reveal:   His chest-x ray and urinalysis results are normal.  Which of the following is the most appropriate pharmacotherapy?

Quizplus · Accepted Answer

Explanation: Vitamin B12 deficiency can present in a subtle manner in the elderly patient. Some patients do not even have anemia, but the majority have an increase in the mean corpuscular volume (MCV). Megaloblastic anemia can be secondary to folic acid or vitamin B12 deficiency, and is characterized by an increase in indirect bilirubin due to ineffective erythropoiesis, as well as pancytopenia or bicytopenia, as in this case. The neurologic presentation includes ataxia, dementia, and occasionally, delirium. (Choice A)Folic acid deficiency is not related to any neurologic abnormalities. (Choice D)Clinically, this is not a case of thiamine deficiency. Thiamine deficiency presents with a classical triad of encephalopathy, oculomotor dysfunction, and gait ataxia, and is usually seen in alcoholics. Furthermore, anemia and elevated MCV are not seen in thiamine deficiency. (Choice E)Even though infection is one of the most common causes of delirium in the elderly, this patient has no other signs or symptoms of infection. He is afebrile. He has no left shift, and his white count is not elevated. (Choice B)Although the patient has pancytopenia, there is no evidence of malignancy. Even if there were malignancy, aggressive chemotherapy could be especially dangerous for a patient of this age. Educational Objective: It is important to recognize vitamin B12 deficiency as a potential cause of delirium or dementia in the elderly patient. Subtle laboratory findings, such as increased MCV and reticulocytes, or pancytopenia, can help to identify this condition.

A 78-Year-Old Healthy, Chinese-American Man Is Brought to the Emergency