ATI RN
ATI RN Pharmacology 2023 Proctored Exam Questions
Question 1 of 5
Mannitol (Osmitrol), an osmotic diuretic, is contraindicated to which conditions? Select all that apply.
Correct Answer: B
Rationale: 1. Narrow-angle glaucoma: Mannitol can exacerbate narrow-angle glaucoma by causing an increase in intraocular pressure. Therefore, it is contraindicated in patients with this condition.
Question 2 of 5
A 6-year-old boy is brought to his primary care physician with a history of hay fever and asthma. He usually has two to three attacks per week. For symptom control, he uses an albuterol inhaler, but his parents would like to try something more. They would like him to take something that would lessen the amount of attacks he has. Although corticosteroids would probably work best for prophylaxis, they are contraindicated in children. He is instead given montelukast. How does montelukast work?
Correct Answer: A
Rationale: Montelukast prevents asthma attacks by blocking leukotriene receptors . Leukotrienes drive inflammation; montelukast reduces this, complementing albuterol's acute relief. Muscarinic blockade is ipratropium's action. COX inhibition (C, D) is NSAIDs'. Lipoxygenase inhibition (E) is zileuton's. Montelukast's specificity suits prophylaxis in this child.
Question 3 of 5
An 80-year-old man is taking digoxin and warfarin because of longstanding atrial fibrillation. He has an indwelling urinary catheter in situ, whilst awaiting a prostatectomy. At his pre-operation assessment he has a ventricular rate of 120/minute. The house officer doubles his daily digoxin dose and the operation is delayed one week. One week later he returns with nausea, vomiting, diarrhoea, abdominal pain, confusion, delirium and visual disturbances. The most likely cause of his current symptoms is:
Correct Answer: D
Rationale: Symptoms (nausea, confusion, visual changes) suggest digoxin toxicity, common in the elderly with doubled doses. Digoxin's narrow therapeutic index (0.5-2 ng/mL) and renal clearance (impaired with age) increase risk. Viral infection lacks cardiac specificity here. Hyperkalemia (e.g., >5.5 mmol/L) isn't indicated without ECG changes. Warfarin's INR prolongation causes bleeding, not these symptoms. UTI fits the catheter but not delirium/visual issues. Digoxin toxicity, from overdose and accumulation, explains the presentation, requiring level checks and cessation.
Question 4 of 5
Enrique who is under chemotherapy has the following CBC results: WBC 5000/mm3, RBC platelet 10,000/mm3. Which of the following is he at risk for?
Correct Answer: B
Rationale: A platelet count of 10,000/mm3 is critically low and places Enrique at significant risk for bleeding. Platelets are essential for blood clotting, and levels below 20,000/mm3 can lead to spontaneous bleeding, such as nosebleeds, gum bleeding, or internal hemorrhage. While a WBC count of 5000/mm3 is within the normal range, reducing the risk of infection, the extremely low platelet count is the primary concern. Angina is unrelated to platelet counts. Therefore, bleeding is the most immediate risk for Enrique.
Question 5 of 5
Regarding phenytoin, all the following are true EXCEPT:
Correct Answer: B
Rationale: Phenytoin's oral bioavailability varies due to formulation and absorption, a true statement. It's highly plasma protein-bound (~90%), not poorly, making that false and the exception. Hepatic enzyme inducers (e.g., rifampicin) enhance its metabolism, true. At higher doses, its elimination shifts to zero-order due to saturated metabolism, true. Half-life ranges from 12-36 hours, also true. High protein binding affects free drug levels, critical for therapeutic monitoring, especially in hypoalbuminemia.