ATI RN
ATI RN Pharmacology Online Practice 2019 A Questions
Question 1 of 5
The nursing instructor prepares to teach student nurses about how mean effective doses of medications are related to clinical practice. As a result of the instruction, what is the best understanding of the student nurses?
Correct Answer: D
Rationale: Mean effective dose (ED50) affects 50% of a population, but individuals vary-some need more or less due to metabolism, weight, or genetics, a clinical reality. Severe side effects aren't 50%-that's toxicity. Ethnic differences influence response, but dose variation is broader. No effect in 50% misreads ED50. Dose adjustment reflects individual pharmacokinetics, key to practice.
Question 2 of 5
A 6-year-old boy presents to his pediatrician for followup of recurrent 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. Which of the following drugs would decrease the amount of asthma attacks by preventing an arachidonic acid derivative from binding to its receptor?
Correct Answer: D
Rationale: Asthma attacks in this case are driven by inflammation, often mediated by leukotrienes, which are arachidonic acid derivatives. The goal is to reduce the frequency of attacks by targeting this pathway. Aspirin inhibits cyclooxygenase (COX), reducing prostaglandins but not leukotrienes, and may even worsen asthma in some patients. Celecoxib is a selective COX-2 inhibitor, also irrelevant to leukotrienes. Ipratropium is an anticholinergic bronchodilator, effective for acute symptom relief but not prophylaxis via arachidonic acid pathways. Montelukast is a leukotriene receptor antagonist, directly preventing leukotrienes from binding to their receptors, thus reducing inflammation and attack frequency. Zileuton (E), while a leukotriene synthesis inhibitor, isn't the best choice here as the question specifies receptor binding prevention, not synthesis inhibition. Montelukast aligns perfectly with the mechanism described, making it the correct answer.
Question 3 of 5
A 66-year-old man with a history of recurrent pulmonary infections and hypertension is managed with ethacrynic acid, which controls his hypertension well. He is often hospitalized and placed on gentamicin for his recurrent pulmonary infections. Which of the following adverse effects must the treating physician be keenly aware of?
Correct Answer: B
Rationale: Gentamicin, an aminoglycoside, risks ototoxicity-hearing loss , especially with repeated use. Ethacrynic acid, a loop diuretic, also has ototoxicity potential, compounding risk. Dizziness , nausea , vertigo , and vomiting (E) occur but are less specific. Monitoring hearing is critical in this scenario.
Question 4 of 5
A 52-year-old overweight man steamroller operator comes to you complaining of itchy, watery eyes and runny nose in the springtime. He says that he has had this problem for as long as he can remember but does not like going to doctors. His wife finally convinced him to come today see what you might be able to do for him. You prescribe cetirizine. Which of the following describes cetirizine's mechanism of action?
Correct Answer: B
Rationale: Cetirizine treats seasonal allergies (itchy eyes, runny nose) by inhibiting H1 receptors . This blocks histamine, relieving symptoms without sedation, ideal for his job. β2 inhibition or stimulation affects airways. α1 stimulation vasoconstricts. H1 inhibition (E) isn't stimulatory. Cetirizine's action ensures efficacy and safety.
Question 5 of 5
The data shown in the table below concern the effects of drugs on transmitter function in the CNS. Which one of the drugs is most likely to alleviate extrapyramidal dysfunction caused by typical antipsychotics?
Correct Answer: C
Rationale: Typical antipsychotics block dopamine D2 receptors, causing extrapyramidal symptoms (EPS) like parkinsonism due to dopamine-acetylcholine imbalance in the basal ganglia. Drugs alleviating EPS often restore this balance. Drug A strongly activates dopamine receptors, mimicking dopamine and potentially countering the blockade, but excessive activation risks psychosis. Drug B moderately boosts dopamine and GABA, offering some benefit but less specificity. Drug C potently blocks muscarinic acetylcholine receptors, reducing cholinergic overactivity that emerges from dopamine depletion, a well-established approach (e.g., benztropine) for EPS relief without worsening psychosis. Drug D enhances GABA, unrelated to EPS mechanisms. Drug E mildly activates dopamine and GABA, insufficient for robust relief. Blocking muscarinic receptors directly addresses the cholinergic excess, making it the most effective and clinically validated strategy for EPS management.