Which of the following medications is used to treat bipolar disorder by stabilizing mood?

Correct Answer: B

Rationale: The correct answer is B: Lithium. Lithium is used to treat bipolar disorder by stabilizing mood. It helps to reduce the frequency and severity of manic episodes. Carbamazepine (A) is also used to treat bipolar disorder, but it primarily targets manic episodes. Sertraline (C) is an antidepressant used to treat depression and anxiety disorders, not bipolar disorder. Lorazepam (D) is a benzodiazepine used to treat anxiety and insomnia, not bipolar disorder. In summary, Lithium is the correct choice as it specifically targets mood stabilization in bipolar disorder.

Correct Answer: A

Rationale: Rationale: Ezetimibe works by inhibiting the absorption of cholesterol in the small intestine. When taken orally, it targets the NPC1L1 protein in the small intestine, preventing cholesterol absorption. This mechanism reduces total cholesterol levels in the blood. - Choice A: Correct. Ezetimibe inhibits cholesterol absorption in the small intestine. - Choice B: Incorrect. HMG-CoA reductase inhibitors like statins work in the liver, not in the small intestine. - Choice C: Incorrect. Ezetimibe does not increase HDL cholesterol levels. - Choice D: Incorrect. Blocking bile acid reabsorption is the mechanism of action of bile acid sequestrants, not ezetimibe.

Correct Answer: A

Rationale: Rationale for Correct Answer A: Amlodipine is a calcium channel blocker, specifically blocking calcium channels in the heart and blood vessels. By inhibiting calcium entry into cells, it reduces muscle contraction and dilates blood vessels, leading to decreased blood pressure. This mechanism is effective in treating hypertension. Summary of Incorrect Choices: B: Inhibiting norepinephrine reuptake is related to antidepressants, not amlodipine. C: Stimulating beta-1 adrenergic receptors would increase heart rate and contractility, opposite of amlodipine's effects. D: Inhibiting sodium reabsorption in the kidneys is a mechanism of diuretics, not calcium channel blockers like amlodipine.

Correct Answer: B

Rationale: The correct answer is B: Methimazole. Methimazole is commonly prescribed for hyperthyroidism as it inhibits the production of thyroid hormones. It is a first-line treatment for this condition. Levothyroxine (A) is used to treat hypothyroidism, not hyperthyroidism. Propranolol (C) is used to manage symptoms of hyperthyroidism like rapid heart rate but does not treat the underlying cause. Amiodarone (D) can actually induce hyperthyroidism as a side effect.

Correct Answer: A

Rationale: The correct answer is A: Blocking the reuptake of serotonin and norepinephrine. Tramadol is a centrally acting opioid analgesic that primarily works by inhibiting the reuptake of serotonin and norepinephrine. This mechanism helps to increase the levels of these neurotransmitters in the brain, leading to pain relief. Choice B is incorrect because tramadol is not a direct opioid agonist. Choice C is incorrect as tramadol does not inhibit acetylcholine. Choice D is incorrect as tramadol does not primarily inhibit prostaglandin synthesis.