A 60-year-old male with chronic asthma is prescribed salmeterol. Salmeterol works by:

Correct Answer: B

Rationale: The correct answer is B because salmeterol is a long-acting beta-2 adrenergic agonist, which works by stimulating beta-2 adrenergic receptors on bronchial smooth muscle, leading to bronchodilation. This helps in relaxation of the airways and improved breathing in asthma patients. Option A is incorrect because salmeterol does not affect histamine release. Option C is incorrect as salmeterol does not inhibit leukotriene receptors. Option D is incorrect as salmeterol does not block acetylcholine receptors.

Correct Answer: B

Rationale: The correct answer is B: Improving insulin sensitivity in peripheral tissues. Metformin helps improve insulin sensitivity by increasing the uptake of glucose by muscle and fat cells, reducing glucose production in the liver, and decreasing insulin resistance. This leads to better control of blood glucose levels in individuals with type 2 diabetes. Choice A is incorrect because metformin does not directly increase insulin secretion from the pancreas. Choice C is incorrect because metformin does not inhibit glucose absorption in the intestines. Choice D is incorrect because although metformin may increase renal glucose excretion to some extent, its primary mechanism of action is improving insulin sensitivity in peripheral tissues.

Correct Answer: B

Rationale: The correct answer is B: Inhibiting HMG-CoA reductase in the liver. Rosuvastatin is a statin medication that works by inhibiting the enzyme HMG-CoA reductase, which is responsible for the production of cholesterol in the liver. By inhibiting this enzyme, rosuvastatin helps lower the levels of LDL cholesterol in the blood. Choices A, C, and D are incorrect because rosuvastatin does not act by inhibiting cholesterol reabsorption in the intestines, increasing HDL cholesterol levels, or increasing the excretion of cholesterol in the bile.

Correct Answer: A

Rationale: The correct answer is A: Muscle pain. Statin drugs are known to cause myopathy, which can manifest as muscle pain, weakness, or tenderness. This adverse effect is due to statins affecting muscle cells and potentially leading to muscle inflammation or damage. Headache (B), weight gain (C), and coughing (D) are not common adverse effects associated with statin drugs. Muscle pain is a well-documented and frequently reported side effect, making it the correct choice in this scenario.

Correct Answer: A

Rationale: The correct answer is A: Constipation. Opioids commonly cause constipation due to their effect on the gastrointestinal tract, slowing down gut motility. This is a well-documented adverse effect of opioid medications. Hypotension (B), weight loss (C), and tachycardia (D) are not common adverse effects of opioids. Hypotension is more associated with vasodilator medications, weight loss is not typically seen with opioids, and tachycardia is more likely to be caused by stimulant medications.