Which of the following statements about progestins is True:

Correct Answer: D

Rationale: Rationale: A: Progesterone is rapidly absorbed as it has high bioavailability. B: Progesterone is metabolized in the liver to pregnanediol and conjugated with glucuronic acid. C: Progestins and their metabolites are excreted in urine, indicating systemic circulation. Therefore, D is correct as all statements are true.

Correct Answer: D

Rationale: Rationale for Choice D (Inhibits calcineurin): 1. Tacrolimus binds to FK-binding protein, forming a complex that inhibits calcineurin. 2. Calcineurin inhibition blocks T-cell activation by preventing dephosphorylation of NFAT, hindering IL-2 production. 3. This suppresses immune response in transplant recipients. Summary: A: Inhibiting CD3 receptor is the mechanism of action of other drugs like anti-CD3 antibodies, not tacrolimus. B: Complement-mediated cytolysis is unrelated to tacrolimus. C: Substitution for deficient immunoglobulins is not the mechanism of action of tacrolimus, which targets T-cell activation.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Clavulanic acid, sulbactam, and tazobactam are all beta-lactamase inhibitors. Beta-lactamase inhibitors work by inactivating the beta-lactamase enzymes produced by bacteria, thus protecting beta-lactam antibiotics. Clavulanic acid, sulbactam, and tazobactam are commonly used in combination with beta-lactam antibiotics to enhance their efficacy. Therefore, choosing D as the correct answer is justified as all the options listed are indeed beta-lactamase inhibitors.

Correct Answer: B

Rationale: Step 1: Clofibrate is associated with higher rates of adverse effects and drug interactions compared to gemfibrozil. Step 2: Gemfibrozil has been shown to be more effective in lowering triglyceride levels. Step 3: Studies have demonstrated that gemfibrozil reduces the risk of cardiovascular events more effectively than clofibrate. Step 4: Therefore, the correct answer is B (FALSE) as gemfibrozil is generally regarded as superior to clofibrate based on safety and efficacy data.

Correct Answer: D

Rationale: The correct answer is D: All of the above. 1. Primary hyperparathyroidism can lead to increased excretion of phosphate in the urine, causing hypophosphatemia. 2. Vitamin D deficiency can result in impaired absorption of phosphate in the intestines, contributing to hypophosphatemia. 3. Idiopathic hypercalciuria can lead to excessive excretion of both calcium and phosphate in the urine, further exacerbating hypophosphatemia. In summary, all three conditions (A, B, and C) are associated with hypophosphatemia due to different mechanisms involving impaired phosphate balance in the body.