Basic & Clinical Pharmacology Book Questions (chapter 2) with 100% Correct Answers Verified | Updated

Basic & Clinical Pharmacology Book Questions (chapter 2) with 100% Correct Answers Verified | Updated Answer - B No information is given regarding the maximal antihypertensive response to either drug. Similarly, no information about half-life or toxicity is provided. The fact that a given response is achieved with a smaller dose of thiazide A indicates that A is more potent than B in the ratio of 500:5. A 55-year-old woman with hypertension is to be treated with a thiazide diuretic. Thiazide A in a dose of 5 mg produces the same decrease in blood pressure as 500 mg of thiazide B. Which of the following statements best describes these results? (A) Thiazide A is more efficacious than thiazide B (B) Thiazide A is about 100 times more potent than thiazide B (C) Toxicity of thiazide A is less than that of thiazide B (D) Thiazide A has a wider therapeutic window than thiazide B (E) Thiazide A has a longer half-life than thiazide B Answer - C Precise quantitation is possible with both types of dose-response curves. Quantal dose-response curves show the frequency of occurrence of a specified response, which may be therapeutically effective (ED) or toxic (TD). Thus, quantal studies are used to determine the therapeutic index and the variation in sensitivity to the drug. Graded (not quantal) dose-response curves are used to determine maximal efficacy (maximal response). Graded and quantal dose-response curves are being used for evaluation of a new antiasthmatic drug in the animal laboratory and in clinical trials. Which of the following statements best describes graded dose-response curves? (A) More precisely quantitated than quantal dose-response curves (B) Obtainable from isolated tissue preparations but not from the study of intact subjects (C) Used to determine the maximal efficacy of the drug (D) Used to determine the therapeutic index of the drug (E) Used to determine the variation in sensitivity of subjects to the drug Answer - D Drug A produces 50% of its maximal