A 65-year-old female with chronic pain is prescribed hydrocodone. Hydrocodone works by:

Correct Answer: A

Rationale: Step-by-step rationale for why choice A is correct: 1. Hydrocodone is an opioid analgesic. 2. Opioid analgesics work by binding to opioid receptors in the brain. 3. By binding to these receptors, hydrocodone modulates pain perception and response. 4. This mechanism of action is how hydrocodone alleviates pain. Summary of why the other choices are incorrect: B: Inhibiting the reuptake of serotonin and norepinephrine - This describes the mechanism of action for antidepressants, not opioids like hydrocodone. C: Inhibiting prostaglandin synthesis - This is the mechanism of action for nonsteroidal anti-inflammatory drugs (NSAIDs), not opioids. D: Blocking sodium channels in peripheral nerves - This is a mechanism seen with local anesthetics, not opioids.

Correct Answer: C

Rationale: The correct answer is C: Reducing inflammation in the airways. Fluticasone is a corticosteroid that works by reducing inflammation in the airways, which helps to control asthma symptoms. Corticosteroids like fluticasone target the underlying inflammation in asthma, leading to decreased airway swelling and mucus production. This helps to improve airflow and reduce asthma symptoms over time. Choice A is incorrect as histamine release inhibition is typically targeted by antihistamines, not corticosteroids like fluticasone. Choice B is incorrect because leukotriene receptor blockers target a different pathway in asthma treatment. Choice D is incorrect as bronchodilation, or relaxing bronchial smooth muscle, is typically achieved by bronchodilator medications like beta-agonists, not corticosteroids.

Correct Answer: A

Rationale: The correct answer is A: Fexofenadine. It is a second-generation antihistamine that helps reduce symptoms of allergic rhinitis by blocking the action of histamine. Histamine is released during an allergic reaction, causing symptoms like sneezing, itching, and runny nose. Ibuprofen (B) is a pain reliever and anti-inflammatory drug, not typically used for allergic rhinitis. Loratadine (C) is another second-generation antihistamine, also used to treat allergic rhinitis. Paracetamol (D) is a pain reliever and fever reducer, not specifically used for allergic rhinitis symptoms.

Correct Answer: A

Rationale: The correct answer is A: Epinephrine. Epinephrine is the most commonly used medication for treating acute anaphylaxis due to its rapid onset of action and ability to reverse severe allergic reactions. It works by constricting blood vessels, increasing heart rate, and opening airways. Diphenhydramine (B) is an antihistamine that can help with mild allergic reactions but is not as effective as epinephrine for anaphylaxis. Albuterol (C) is a bronchodilator used for asthma and may help with airway constriction in some cases of anaphylaxis, but it is not the first-line treatment. Prednisone (D) is a corticosteroid that can help reduce inflammation but is not fast-acting enough for the immediate treatment of anaphylaxis.

Correct Answer: A

Rationale: The correct answer is A. Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor, which works by inhibiting the conversion of angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor that increases blood pressure. By inhibiting its production, lisinopril helps dilate blood vessels, reduce blood pressure, and improve blood flow. This mechanism is crucial in managing hypertension. Choice B is incorrect because beta-blockers, not ACE inhibitors like lisinopril, block beta-adrenergic receptors in the heart to reduce heart rate and blood pressure. Choice C is incorrect because while lisinopril does relax vascular smooth muscle, the primary mechanism is through angiotensin II inhibition. Choice D is incorrect because lisinopril does not directly affect sodium excretion in the kidneys; instead, it primarily targets the renin-angiotensin-aldosterone system to regulate blood