ATI RN
Cardiovascular System Drugs Classification Questions
Question 1 of 5
Acetylcholine is not used in clinical practice because:
Correct Answer: C
Rationale: Acetylcholine is not used in clinical practice because it is very rapidly hydrolyzed by the enzyme acetylcholinesterase. Upon administration, it quickly breaks down before exerting its desired effects. This rapid hydrolysis limits its therapeutic efficacy, making it unsuitable for clinical use. Other choices (A, B, D) are incorrect as acetylcholine's lack of use is primarily due to its rapid degradation, not its toxicity, high doses requirement, or costliness.
Question 2 of 5
A nonselective beta receptor agonist causes all of the following effects EXCEPT:
Correct Answer: B
Rationale: Correct Answer: B (Increase peripheral arterial resistance) Rationale: Nonselective beta receptor agonists stimulate beta-1 and beta-2 receptors. Activation of beta-1 receptors on the heart increases cardiac output (A). Activation of beta-2 receptors in peripheral arteries causes vasodilation, leading to a decrease in peripheral arterial resistance (C). Mean arterial pressure is determined by cardiac output and peripheral resistance, so decreasing peripheral resistance would not directly lead to a decrease in the mean pressure (D). Therefore, the correct answer is B because nonselective beta receptor agonists do not increase peripheral arterial resistance.
Question 3 of 5
Which of the following agents is a beta2–selective antagonist?
Correct Answer: D
Rationale: The correct answer is D: Butoxamine. Butoxamine is a beta2-selective antagonist due to its high affinity for beta2-adreagent receptors over beta1 receptors. This selectivity allows it to block the effects of beta2 activation specifically. Tolazoline (A) is an alpha-adrenergic antagonist, Pindolol (B) is a non-selective beta-blocker, and Ergotamine (C) is a serotonin receptor agonist. Therefore, they are not beta2-selective antagonists.
Question 4 of 5
Indicate the barbituric acid derivative which has 4-5 days elimination half-life:
Correct Answer: C
Rationale: The correct answer is C: Phenobarbital. Phenobarbital has a longer elimination half-life of 4-5 days due to its extensive hepatic metabolism and slow excretion. Secobarbital (A) has a shorter half-life around 15 hours. Thiopental (B) has a very short half-life of 5-10 hours. Amobarbital (D) has a half-life of around 10-25 hours, making it shorter than phenobarbital. Therefore, based on the pharmacokinetics of these drugs, phenobarbital is the most likely choice with a 4-5 days elimination half-life.
Question 5 of 5
The antiseizure drug, which induces hepatic microsomal enzymes, is:
Correct Answer: B
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.