A 50-year-old male with depression is prescribed fluoxetine. Fluoxetine works by:

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: 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.

Correct Answer: A

Rationale: The correct answer is A: Efavirenz. Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI) used in HIV/AIDS management by inhibiting the reverse transcriptase enzyme. It works by binding to the enzyme, preventing the conversion of RNA to DNA in the virus. Amoxicillin (B) is an antibiotic used for bacterial infections, Clarithromycin (C) is also an antibiotic for bacterial infections, and Fluconazole (D) is an antifungal medication. These choices do not target the reverse transcriptase enzyme involved in HIV replication, making them incorrect for managing HIV/AIDS.

Correct Answer: B

Rationale: The correct answer is B because tramadol primarily works by inhibiting the reuptake of serotonin and norepinephrine in the brain. This mechanism of action helps to modulate pain signals and increase pain tolerance. Choice A is incorrect because tramadol has weak affinity for opioid receptors. Choice C is incorrect as tramadol does not inhibit prostaglandin synthesis like NSAIDs. Choice D is incorrect as blocking sodium channels is the mechanism of action for local anesthetics, not tramadol.