ATI RN
Introduction to Pharmacology ATI Quizlet Questions
Question 1 of 5
The following agents induce hepatic CYP450:
Correct Answer: A
Rationale: Rifampicin is a potent inducer of CYP450 enzymes, increasing the metabolism of drugs processed via these pathways.
Question 2 of 5
What is the rationale for combining levodopa with carbidopa?
Correct Answer: B
Rationale: Levodopa treats Parkinson's by crossing the blood-brain barrier and converting to dopamine, but peripheral metabolism by dopa decarboxylase reduces its availability and causes side effects like nausea. Carbidopa, a peripheral dopa decarboxylase inhibitor, doesn't cross into the CNS, so it prevents levodopa breakdown outside the brain, increasing its CNS entry and efficacy. It doesn't stimulate dopamine receptors—levodopa's metabolite does that. Absorption isn't directly enhanced; bioavailability improves due to less peripheral loss. Peripheral dopamine production decreases with carbidopa, not increases, reducing side effects. COMT inhibition (e.g., entacapone) is a separate strategy. By blocking peripheral conversion, carbidopa ensures more levodopa reaches the brain, optimizing therapy and minimizing adverse effects.
Question 3 of 5
Indicate the spot of the median effective dose on the frequency distribution curve.
Correct Answer: C
Rationale: Median effective dose (ED50) is where 50% of subjects respond, typically the curve's midpoint (marked ED50), per pharmacodynamic curves. Beginning lacks response. Ascending leg is below 50%. Descending leg is post-peak. ED50's position defines it, aligning with standard graphs.
Question 4 of 5
Alprazolam's therapeutic use is what?
Correct Answer: B
Rationale: Alprazolam is a medication commonly used in treating anxiety disorders, panic disorders, and anxiety associated with depression. It belongs to a class of drugs known as benzodiazepines, which act on the central nervous system to produce a calming effect. Alprazolam helps to reduce feelings of anxiety and promote relaxation by enhancing the activity of certain neurotransmitters in the brain. It is not used for relief of drowsiness, bronchospasms, or cardiac arrest.
Question 5 of 5
The nurse is determining a patient's gastric residual before administering an enteral feeding; the last feeding was 240 mL. The patient will be discharged on enteral feedings. It is important to include in the teaching plan that a residual of more than which amount would indicate delayed gastric emptying (based on the last feeding)?
Correct Answer: A
Rationale: A gastric residual volume of more than 60 mL (or 25% of the last feeding) suggests delayed gastric emptying, which increases the risk of aspiration. The nurse should hold the feeding and reassess if the residual exceeds this threshold. Higher residuals (B, C, D) are not acceptable indicators.