Sugar molecules in the structure of glycosides influence:

Correct Answer: D

Rationale: The correct answer is D: All of the above. Sugar molecules in glycosides can affect cardiotonic action by enhancing heart function, impact pharmacokinetic properties by influencing drug absorption and metabolism, and contribute to toxic properties by affecting bioavailability and toxicity. Therefore, all the options (A, B, C) are influenced by sugar molecules in glycosides.

Correct Answer: D

Rationale: The correct answer is D because the main principle of shock treatment is to improve peripheral blood flow to vital organs and tissues. By improving peripheral blood flow, oxygen and nutrients can reach affected areas, helping to restore cellular function. Increasing arterial pressure (A) may worsen tissue perfusion, increasing peripheral vascular resistance (B) can further impair blood flow, and increasing cardiac output (C) may not address the underlying issue of poor peripheral blood flow in shock conditions.

Correct Answer: A

Rationale: The correct answer is A because hypothyroidism is indeed a syndrome caused by a deficiency of thyroid hormones, leading to a slowdown of body functions. This is supported by clinical manifestations such as fatigue, weight gain, and cold intolerance. Choice B is incorrect as it describes hyperthyroidism, not hypothyroidism. Choice C refers to severe hypothyroidism in adults and is not a statement. Choice D is a form of severe congenital hypothyroidism, not a statement about hypothyroidism in general. Therefore, choice A is the only accurate statement among the options.

Correct Answer: C

Rationale: Sure. Tamoxifen is classified as an antiestrogen because it competitively binds to estrogen receptors, blocking the effects of estrogen. It is commonly used in breast cancer treatment to inhibit estrogen-stimulated tumor growth. Antiprogestins (choice A) block progesterone effects, not estrogen. Antiandrogens (choice B) block androgen effects, not estrogen. Androgens (choice D) are male sex hormones, unrelated to tamoxifen's mechanism of action.

Correct Answer: C

Rationale: The correct answer is C: Zafirlukast (Accolate). Zafirlukast is a leukotriene receptor antagonist that specifically blocks the action of leukotriene D4 (LTD4) at its receptor. This drug helps in reducing inflammation in conditions like asthma by blocking the effects of LTD4. Ibuprofen (A) and Diclofenac (D) are nonsteroidal anti-inflammatory drugs (NSAIDs) that work by inhibiting cyclooxygenase enzymes. Zileuton (B) is a 5-lipoxygenase inhibitor that blocks the formation of leukotrienes but does not specifically target the LTD4 receptor. Therefore, the correct choice is C as it directly blocks the LTD4 receptor, unlike the other options.