ATI RN
Pharmacology Across the Lifespan Quizlet Questions
Question 1 of 5
A patient with heart failure is prescribed spironolactone. Spironolactone works by:
Correct Answer: B
Rationale: Step-by-step rationale for choice B: 1. Spironolactone is a mineralocorticoid receptor antagonist. 2. It blocks aldosterone receptors in the kidneys. 3. Aldosterone is a hormone that promotes sodium and water retention, leading to increased blood volume and pressure. 4. By blocking aldosterone receptors, spironolactone reduces sodium and water retention, helping to decrease blood volume and pressure in heart failure patients. Summary of why other choices are incorrect: A: Inhibiting sodium reabsorption in the kidneys is the mechanism of action of loop diuretics, not spironolactone. C: Spironolactone actually increases potassium retention, not excretion. D: Increasing cardiac contractility is the mechanism of action of positive inotropic agents, not spironolactone.
Question 2 of 5
Drugs with low efficacy bind to receptors but do not fully activate them. Such 'partial agonists' can act as either a weak agonist (in the absence of a full agonist), or as a competitive antagonist (if a full agonist is present). Which curve best reflects the effect produced by this type of agonist when it is administered alone?
Correct Answer: B
Rationale: The correct answer is B because a partial agonist binds to receptors but only partially activates them, resulting in a submaximal response. Curve B depicts a submaximal response that is lower than the maximal response achieved with a full agonist but higher than the response with no agonist. Curve A represents a full agonist with a maximal response, not a partial agonist. Curve C shows no response, which does not align with the partial agonist's characteristic of producing a submaximal response. Curve D depicts an inverse agonist that decreases the basal activity of receptors, not the partial agonist's partial activation. Therefore, the best representation of a partial agonist's effect when administered alone is Curve B.
Question 3 of 5
This drug can act as an agonist at serotonergic and α-adrenergic receptors.
Correct Answer: B
Rationale: The correct answer is B: Ergonovine. Ergonovine is a drug that can act as an agonist at serotonergic and α-adrenergic receptors. Serotonergic receptors are important in regulating mood and behavior, while α-adrenergic receptors are involved in various physiological processes. Cyproheptadine (A) is a serotonin antagonist, Loratadine (C) is an antihistamine, and Promethazine (D) is a histamine antagonist and dopamine antagonist. Therefore, they do not act as agonists at serotonergic and α-adrenergic receptors.
Question 4 of 5
A 34-year-old man presented to his physician complaining of dry mouth, constipation, and difficulty in urination. He also noticed an increase in appetite. The man had started a therapy with cyproheptadine 2 weeks earlier to treat cold-induced urticaria. Drug-induced blockade of which of the following pairs of receptors most likely mediated the patient's symptoms?
Correct Answer: B
Rationale: The correct answer is B: H1-histaminergic and muscarinic receptors. Cyproheptadine is an antihistamine that blocks H1-histaminergic receptors, leading to dry mouth and increased appetite. Blockade of muscarinic receptors can cause constipation and difficulty in urination. A: Dopaminergic and α1-adrenergic receptors are not typically associated with the symptoms described. C: Blocking α1-adrenergic receptors alone would not explain the urinary symptoms, and dopamine is not involved in these symptoms. D: Serotonergic and GABAergic receptors are not typically associated with these symptoms.
Question 5 of 5
A 53-year-old man presented to the clinic complaining of itching, flushing, arthralgia, heartburn, and diarrhea. Further exams led to the diagnosis of systemic mastocytosis. Which of the following pairs of drugs should be included in the therapeutic treatment of this patient?
Correct Answer: C
Rationale: The correct answer is C: Loratadine and famotidine. Loratadine is an antihistamine that can help alleviate itching and flushing by blocking the action of histamine released during mast cell activation. Famotidine is a histamine H2 receptor antagonist that can reduce heartburn symptoms by decreasing stomach acid production. Misoprostol (choice B) is used to prevent ulcers but is not directly related to mastocytosis treatment. Aspirin and ergotamine (choice A) can worsen symptoms in mastocytosis patients due to their potential to trigger mast cell degranulation. Diphenhydramine (choice D) is an antihistamine but is not as effective as loratadine in controlling symptoms of mastocytosis. Therefore, the best therapeutic approach for this patient is to use loratadine and famotidine to manage his symptoms effectively.