A 55-year-old female with osteoarthritis is prescribed celecoxib. Celecoxib works by:

Correct Answer: A

Rationale: The correct answer is A: Inhibiting COX-2 enzymes selectively. Celecoxib is a selective COX-2 inhibitor, which means it specifically targets the cyclooxygenase-2 enzyme responsible for inflammation and pain without affecting COX-1 enzymes that protect the stomach lining. This selective inhibition reduces inflammation and pain while minimizing the risk of gastrointestinal side effects associated with non-selective NSAIDs. Choice B is incorrect because celecoxib does not inhibit both COX-1 and COX-2 enzymes. Choice C is incorrect because celecoxib does not increase prostaglandin synthesis; it actually reduces it by inhibiting COX-2. Choice D is incorrect because celecoxib does not block sodium channels in peripheral nerves; its mechanism of action is through selective COX-2 inhibition.

Correct Answer: B

Rationale: Rationale: 1. Type 1 diabetes is characterized by the body's inability to produce insulin. 2. Insulin is the primary treatment for type 1 diabetes as it replaces the missing hormone. 3. Metformin (choice A) is typically used for type 2 diabetes. 4. Sulfonylureas (choice C) and Glinides (choice D) stimulate insulin production, not suitable for type 1 diabetes.

Correct Answer: B

Rationale: The correct answer is B: Inhibiting COX-2 enzymes selectively. Celecoxib is a selective COX-2 inhibitor, meaning it specifically targets and inhibits the cyclooxygenase-2 enzyme, which is responsible for producing prostaglandins involved in inflammation and pain. By selectively inhibiting COX-2, celecoxib reduces inflammation and pain without affecting COX-1, which helps maintain the stomach lining and platelet function. Choice A (Inhibiting COX-1 and COX-2 enzymes) is incorrect because celecoxib primarily targets COX-2, not COX-1. Choice C (Binding to opioid receptors in the brain) is incorrect as celecoxib does not bind to opioid receptors but works through a different mechanism. Choice D (Inhibiting the synthesis of leukotrienes) is incorrect as celecoxib does not directly inhibit leukotriene synthesis; it primarily inhibits COX-2 enzymes

Correct Answer: B

Rationale: The correct answer is B: Inhibiting the action of HMG-CoA reductase in the liver. Pravastatin is a statin medication that works by inhibiting the enzyme HMG-CoA reductase, which plays a key role in the liver's production of cholesterol. By blocking this enzyme, pravastatin reduces the liver's ability to produce cholesterol, leading to lower levels of LDL cholesterol in the bloodstream. This mechanism helps to lower the risk of cardiovascular events in patients with hyperlipidemia. Choice A is incorrect because pravastatin does not inhibit the absorption of cholesterol in the intestines; it primarily acts in the liver. Choice C is incorrect because pravastatin primarily lowers LDL cholesterol levels rather than increasing HDL cholesterol levels. Choice D is incorrect because blocking bile acid reabsorption is not the primary mechanism of action of pravastatin in managing hyperlipidemia.

Correct Answer: B

Rationale: The correct answer is B: Binding to opioid receptors in the central nervous system. Oxycodone is an opioid analgesic that exerts its effects by binding to opioid receptors in the brain and spinal cord, which modulates pain perception. This mechanism of action is how oxycodone provides pain relief. A: Blocking sodium channels in peripheral nerves is incorrect because this mechanism is associated with local anesthetics, not opioids like oxycodone. C: Increasing the release of serotonin is incorrect as oxycodone does not directly affect serotonin levels. D: Inhibiting the reuptake of norepinephrine is incorrect as this is a mechanism seen in certain antidepressants, not opioids like oxycodone.