ATI RN
ATI Pharmacology Practice B Questions
Question 1 of 5
A child is experiencing absence seizures that interrupt his ability to pay attention during school and activities. Which of the following therapies would be most appropriate for this patient?
Correct Answer: A
Rationale: Ethosuximide treats absence seizures by blocking T-type calcium channels in thalamic neurons, reducing 3 Hz spike-and-wave discharges that disrupt attention, ideal for school-aged children. Carbamazepine, a sodium channel blocker, controls focal and tonic-clonic seizures but worsens absence seizures. Diazepam manages acute seizures, not chronic absence. Carbamazepine plus primidone targets other seizure types, not absence. Watchful waiting risks educational impact. Ethosuximide's specificity, efficacy, and pediatric safety make it the most appropriate, per guidelines.
Question 2 of 5
The following drugs obey non-linear (dose-dependent) elimination pharmacokinetics:
Correct Answer: C
Rationale: Phenytoin exhibits non-linear kinetics because its elimination pathways become saturated at therapeutic doses, leading to a disproportionate rise in plasma levels with dose increases.
Question 3 of 5
A patient has received an overdose of intravenous heparin, and is showing signs of excessive bleeding. Which substance is the antidote for heparin overdose?
Correct Answer: C
Rationale: Protamine sulfate is the antidote for heparin overdose. Heparin is a commonly used anticoagulant medication that works by inhibiting the activity of thrombin and preventing blood clot formation. In the case of an overdose leading to excessive bleeding, protamine sulfate can be administered to neutralize the effects of heparin. Protamine sulfate forms a complex with heparin, therefore reversing its anticoagulant effects and helping to stop the bleeding. This antidote is especially useful in situations where immediate reversal of heparin's effects is necessary to prevent serious complications.
Question 4 of 5
Which of the following drugs is likely to increase the plasma lithium concentration if co-prescribed to a patient on chronic lithium therapy?
Correct Answer: B
Rationale: Lithium levels rise with drugs reducing renal clearance or altering metabolism. St John's wort induces CYP enzymes, potentially lowering lithium (not renally metabolized). Ibuprofen, an NSAID, reduces renal lithium excretion by inhibiting prostaglandins, increasing plasma levels, a well-known interaction. Phenytoin induces metabolism but doesn't affect lithium's renal clearance. Haloperidol and sertraline have minimal pharmacokinetic impact on lithium. Ibuprofen's effect necessitates monitoring, as elevated lithium risks toxicity (e.g., tremor, confusion), critical in bipolar management.
Question 5 of 5
The physician prescribes fluticasone (Flonase) for the client. The nurse would hold the drug and contact the physician with which assessment finding?
Correct Answer: B
Rationale: Fluticasone, Category C, requires caution in pregnancy , prompting physician consultation due to fetal risk uncertainty. Diabetes , glaucoma , and hypertension aren't immediate holds. B ensures safety, making it the key finding.