Mechanism of aminosalicylic acid action is:

Correct Answer: B

Rationale: The correct answer is B: Inhibition of folate synthesis. Aminosalicylic acid acts by inhibiting the enzyme dihydropteroate synthase in the folate synthesis pathway of bacteria. This disrupts the production of essential folate cofactors needed for DNA and RNA synthesis, ultimately leading to bacterial growth inhibition. Incorrect choices: A: Inhibition of mycolic acids synthesis - This mechanism is associated with drugs like isoniazid in the treatment of mycobacterial infections. C: Inhibition of DNA dependent RNA polymerase - This mechanism is associated with drugs like rifampin. D: Inhibition of DNA gyrase - This mechanism is associated with drugs like fluoroquinolones.

Correct Answer: D

Rationale: The correct answer is D: Epinephrine. Epinephrine is a vasopressor and bronchodilator used in emergency situations like dyspnea to improve breathing and increase blood pressure. Hydrochlorothiazide and Amiloride are diuretics used to treat hypertension and edema, not acute dyspnea. Mannitol is an osmotic diuretic used to reduce intracranial pressure, not for dyspnea. Epinephrine is the most appropriate choice for immediate relief of dyspnea due to its bronchodilator effects and ability to improve breathing quickly.

Correct Answer: B

Rationale: The correct answer is B: Blockade of Na+ channels in the collecting duct. This action prevents Na+ reabsorption, leading to increased Na+ in the urine and decreased K+ secretion. This mechanism is seen in potassium-sparing diuretics like amiloride and triamterene. Choices A and C do not directly impact potassium sparing. Choice D is incorrect as aldosterone receptor blockade would lead to increased K+ excretion.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.