ATI RN
Practice ATI B Exam Pharmacology Questions
Question 1 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 2 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.
Question 3 of 5
The nurse plans medication education for a client who receives a prescription for sildenafil (Viagra). What will the best plan by the nurse include?
Correct Answer: C
Rationale: Sildenafil (Viagra), a phosphodiesterase-5 inhibitor, has a dosing limit of one pill per 24 hours to avoid risks like prolonged erections or hypotension, a key safety point for education. Grapefruit juice increases sildenafil levels by inhibiting metabolism, not decreasing effects, risking intensified side effects. It's optimally taken 1 hour before sex, effective up to 4 hours-not 6-setting realistic timing expectations. Food, especially high-fat meals, delays absorption, so it's best on an empty stomach. The 24-hour limit ensures safe use, balancing efficacy with minimizing adverse effects, aligning with prescribing standards and making it the priority in client teaching.
Question 4 of 5
Prior to administering medications, the student nurse reviews the therapeutic index. Which statement best describes the student's understanding of therapeutic index?
Correct Answer: B
Rationale: Therapeutic index (TI), the ratio of toxic to effective dose, gauges safety-wide TI means safer dosing, helping the student assess if doses are within safe limits. Best drug choice is clinical, not TI-based. Interactions aren't TI-specific. Monitoring needs tie to narrow TI drugs (e.g., lithium), but safety is broader. TI ensures safe dosing, a key review point.
Question 5 of 5
The patient has been receiving escitalopram (Lexapro) for treatment of obsessive-compulsive disorder. Unknown to the nurse, the patient has also been self-medicating with St. John's wort. The patient comes to the office with symptoms of hyperthermia and diaphoresis. Which statement best describes the result of the nurse's assessment?
Correct Answer: D
Rationale: Escitalopram and St. John's wort, both serotonin boosters, risk serotonin syndrome-hyperthermia, diaphoresis-per pharmacology. St. John's toxicity alone (e.g., photosensitivity) doesn't fit. They're not safe together-interaction is known. Withdrawal lacks agitation context. Serotonin excess explains symptoms, a critical finding.