Which of the following medications is used to reduce symptoms of allergies by blocking histamine receptors?

Correct Answer: D

Rationale: Certainly! The correct answer is D because all three medications, Diphenhydramine, Loratadine, and Cetirizine, are antihistamines that work by blocking histamine receptors. Diphenhydramine is a first-generation antihistamine with sedating effects, Loratadine is a second-generation antihistamine with non-sedating properties, and Cetirizine is also a second-generation antihistamine. Therefore, all of these medications can effectively reduce allergy symptoms by blocking histamine receptors. The other choices are incorrect because each of them individually is a valid antihistamine used for allergy relief.

Correct Answer: A

Rationale: The correct answer is A: Inhibiting the reuptake of serotonin in the brain. Fluoxetine, a selective serotonin reuptake inhibitor (SSRI), works by blocking the reuptake of serotonin in the brain, leading to increased levels of serotonin available in the synaptic cleft. This helps regulate mood and alleviate symptoms of depression. Summary: - B: Increasing the release of norepinephrine and dopamine: This is incorrect as fluoxetine specifically targets serotonin reuptake, not norepinephrine or dopamine. - C: Blocking serotonin receptors: This is incorrect as fluoxetine does not block serotonin receptors but rather inhibits its reuptake. - D: Inhibiting the reuptake of dopamine: This is incorrect as fluoxetine primarily affects serotonin reuptake, not dopamine.

Correct Answer: B

Rationale: The correct answer is B: Reducing inflammation in the airways. Budesonide is a corticosteroid that works by reducing inflammation in the airways, making it an effective treatment for asthma. Inflammation in the airways is a key factor in asthma symptoms, and corticosteroids like budesonide help to decrease this inflammation, thereby improving breathing and reducing asthma symptoms. Choices A, C, and D are incorrect because budesonide does not work by blocking leukotriene receptors, inhibiting histamine release, or relaxing bronchial smooth muscle. Instead, its main mechanism of action is through its anti-inflammatory properties.

Correct Answer: D

Rationale: The correct answer is D because all three medications (Diphenhydramine, Cetirizine, and Loratadine) are antihistamines that work by blocking histamine receptors to relieve symptoms of allergic rhinitis. Diphenhydramine is a first-generation antihistamine, while Cetirizine and Loratadine are second-generation antihistamines with longer durations of action and less sedation. Therefore, choosing all of the above encompasses the various antihistamines commonly used to treat allergic rhinitis effectively.

Correct Answer: B

Rationale: The correct answer is B: Inhibiting HMG-CoA reductase in the liver. Simvastatin is a statin medication that works by inhibiting the enzyme HMG-CoA reductase in the liver, which plays a key role in cholesterol synthesis. By inhibiting this enzyme, simvastatin reduces the production of cholesterol in the liver, leading to a decrease in LDL cholesterol levels in the bloodstream. Choices A, C, and D are incorrect because simvastatin does not directly affect cholesterol absorption in the intestines, increase HDL cholesterol levels, or increase the excretion of cholesterol in the bile.