Antienzymes are:

Correct Answer: A

Rationale: The correct answer is A because antienzymes are agents that inhibit or destroy enzymic activity. They can be inhibitory enzymes or antibodies that target specific enzymes. This definition aligns with the concept of antienzymes acting to retard or inhibit enzymatic activity. Choice B is incorrect because substances that prevent vitamins from exerting their effects are not related to antienzymes. Choice C describes enzymes, not antienzymes, which are the opposite in function. Choice D refers to coenzymes, which are required for enzyme activity, not antienzymes that inhibit or destroy enzymic activity.

Correct Answer: D

Rationale: The correct answer is D: Probucol (Lorelco). Probucol blocks the oxidation of low-density lipoproteins (LDL) by inhibiting the formation of lipid peroxides. This is important in preventing the development of atherosclerosis. Lovastatin (A) works by inhibiting cholesterol synthesis, Nicotinic acid (B) lowers LDL and triglycerides but does not specifically block oxidation, and Gemfibrozil (C) decreases triglyceride levels but does not directly block LDL oxidation.

Correct Answer: C

Rationale: The correct answer is C: Oral. Alendronate is typically administered orally as it is a bisphosphonate used in the treatment of osteoporosis. The oral route ensures optimal absorption in the gastrointestinal tract. Intravenous and subcutaneous routes are not commonly used for alendronate due to potential adverse effects and practicality issues. Intranasal route is not a common administration method for alendronate. In summary, the oral route is preferred for alendronate administration due to its efficacy, safety, and convenience compared to other routes.

Correct Answer: A

Rationale: The correct answer is A: Loop diuretics. Loop diuretics are the most potent diuretics because they act on the thick ascending limb of the loop of Henle, where they inhibit sodium and chloride reabsorption, leading to significant diuresis. This mechanism results in a higher diuretic effect compared to other classes of diuretics. Thiazide diuretics (B) act on the distal convoluted tubule and are less potent. Potassium-sparing diuretics (C) work on the collecting duct and have a weaker diuretic effect. Carbonic anhydrase inhibitors (D) work on the proximal tubule and are considered mild diuretics compared to loop diuretics.

Correct Answer: C

Rationale: Cephalosporins are broad-spectrum antibiotics effective against both gram-positive and gram-negative bacteria. They are commonly used when penicillins are ineffective. This makes choice C the correct answer, as it accurately reflects the versatility and effectiveness of cephalosporins. A: Gram-positive microorganisms - Incorrect. Cephalosporins are effective against both gram-positive and gram-negative bacteria. B: Gram-negative microorganisms - Incorrect. Cephalosporins are effective against both gram-positive and gram-negative bacteria. D: Only bacteroide infections - Incorrect. Cephalosporins are effective against a wide range of bacteria, not limited to just bacteroide infections.