A 70-year-old female is prescribed hydroxyzine. Hydroxyzine works primarily by:

Correct Answer: A

Rationale: The correct answer is A: Blocking histamine receptors in the brain. Hydroxyzine is a first-generation antihistamine that exerts its effects by blocking histamine receptors, leading to its antihistaminic, sedative, and anxiolytic properties. The other choices (B, C, and D) are incorrect because hydroxyzine does not primarily affect serotonin levels, acetylcholine receptors, or opioid receptors in the brain. Serotonin reuptake inhibitors, anticholinergics, and opioids work through different mechanisms compared to hydroxyzine.

Correct Answer: B

Rationale: The correct answer is B: Improving insulin sensitivity in peripheral tissues. Metformin enhances the response of peripheral tissues to insulin, allowing for better utilization of glucose, reducing blood sugar levels. This mechanism helps to decrease insulin resistance, a key feature in type 2 diabetes. Other choices are incorrect because metformin does not directly increase insulin secretion from the pancreas (choice A), inhibit glucose absorption in the intestine (choice C), or increase the excretion of glucose in the urine (choice D). These mechanisms do not align with how metformin primarily works to improve glucose control in type 2 diabetes.

Correct Answer: A

Rationale: The correct answer is A: Epinephrine. Epinephrine is the drug of choice for treating anaphylaxis due to its rapid action in constricting blood vessels, relaxing smooth muscles, and opening airways. It helps counteract the severe allergic reaction and can save a person's life. Diphenhydramine (B) is an antihistamine that can help relieve itching and hives but is not as effective or fast-acting as epinephrine in treating anaphylaxis. Loratadine (C) is also an antihistamine, which is used for allergies but not for immediate treatment of anaphylaxis. Ibuprofen (D) is a nonsteroidal anti-inflammatory drug (NSAID) used for pain relief and inflammation, but it does not have the life-saving properties needed to treat anaphylaxis.

Correct Answer: A

Rationale: The correct answer is A: Cough and throat irritation. Albuterol is a bronchodilator commonly used to treat asthma and COPD. The mechanism of action of albuterol can lead to irritation of the throat and trigger coughing as a common adverse effect. This is due to the stimulation of beta-2 adrenergic receptors in the airways, causing relaxation of the smooth muscles but also potentially irritating the throat lining. Choices B, C, and D are incorrect because constipation, hypertension, and increased urination are not typically associated with albuterol inhalation therapy.

Correct Answer: B

Rationale: The correct answer is B: Sedation. Opioid analgesics commonly cause sedation due to their central nervous system depressant effects. They act on opioid receptors in the brain, leading to drowsiness and sedation. Diarrhea (A) is more commonly associated with opioid-induced constipation. Hypertension (C) is not a common adverse effect of opioids; they are more likely to cause hypotension. Hypokalemia (D) is not directly linked to opioid use. Sedation is the most prevalent adverse effect of opioids, making it the correct choice here.