Which of the following antienzymes is a monoamine oxidase (MAO) inhibitor:

Correct Answer: B

Rationale: Selegiline is the correct answer as it is a monoamine oxidase (MAO) inhibitor. MAO inhibitors block the breakdown of monoamine neurotransmitters such as dopamine, serotonin, and norepinephrine. Physostigmine is an acetylcholinesterase inhibitor, not an MAO inhibitor. Acetazolamide is a carbonic anhydrase inhibitor used in glaucoma and altitude sickness. Disulfiram is an aldehyde dehydrogenase inhibitor used in alcohol aversion therapy.

Correct Answer: D

Rationale: Step-by-step rationale for the correct answer (D): 1. Pamidronate is a bisphosphonate used to treat conditions involving excessive bone breakdown. 2. Hypercalcemia is a condition characterized by elevated calcium levels in the blood. 3. Pamidronate works by inhibiting bone resorption, which helps lower blood calcium levels in hypercalcemia. 4. Therefore, the indication for pamidronate administration is hypercalcemia. Summary of other choices: A: Failure of vitamin D formation in skin - Not related to pamidronate use. B: Hypoparathyroidism - Pamidronate is not indicated for hypoparathyroidism. C: Elevated skeletal turnover - While pamidronate is used for conditions involving high skeletal turnover, hypercalcemia is the primary indication for its administration.

Correct Answer: D

Rationale: The correct answer is D: Carbonic anhydrase inhibitors. These drugs act at the proximal tubule by inhibiting the enzyme carbonic anhydrase, which leads to decreased reabsorption of bicarbonate and sodium. This results in increased urinary excretion of bicarbonate and sodium, leading to diuresis. Loop diuretics (A) act at the thick ascending limb of the loop of Henle, thiazide diuretics (B) act at the distal convoluted tubule, and potassium-sparing diuretics (C) act at the collecting duct. Therefore, choices A, B, and C are incorrect as they do not target the proximal tubule.

Correct Answer: A

Rationale: The correct answer is A: Penicillin G. This is because Penicillin G has a shorter duration of action compared to the other choices. B, C, and D are all forms of long-acting penicillin preparations designed for sustained release over an extended period. Penicillin G, on the other hand, is a short-acting formulation that requires more frequent dosing due to its rapid elimination from the body. Therefore, Penicillin G does not demonstrate a prolonged effect like the other options.

Correct Answer: A

Rationale: The correct answer is A: Decrease mycobacterium drug-resistance. Combined chemotherapy of tuberculosis involves using multiple drugs to target different stages of the bacteria's life cycle, reducing the chances of resistance developing. This approach is effective in preventing the bacteria from adapting and becoming resistant to any single drug. Explanation: 1. Using multiple drugs targets different mechanisms of action, making it harder for the bacteria to develop resistance. 2. Combination therapy can also prevent the growth of drug-resistant strains by attacking the bacteria from multiple angles. 3. By reducing the likelihood of resistance, combined chemotherapy increases the effectiveness of treatment and improves patient outcomes. Summary: B: Increase mycobacterium drug-resistance - This is incorrect as combined chemotherapy aims to decrease, not increase, drug resistance. C: Decrease the antimicrobial activity - This is incorrect as combined chemotherapy actually enhances the antimicrobial activity against the tuberculosis bacteria. D: Decrease the onset of antimycobacterial drugs biotransformation - This is