A patient is in an urgent care center and is receiving treatment for mild hyponatremia after spending several hours doing gardening work in the heat of the day. The nurse expects that which drug therapy will be used to treat this condition?

Correct Answer: C

Rationale: In the context of mild hyponatremia, which is a condition where there is a lower-than-normal concentration of sodium in the blood, treatment often involves administering intravenous normal saline infusion administered slowly. This helps to incrementally increase sodium levels in the blood while also ensuring proper hydration. Normal saline is preferred over other fluid solutions as it helps to maintain a stable electrolyte balance. In cases of severe hyponatremia or symptoms like seizures, more aggressive treatment may be necessary, but for mild cases like that described in the scenario, normal saline infusion is typically the appropriate choice.

Correct Answer: A

Rationale: Acetaminophen overdose initially presents asymptomatically, but its toxic metabolite, NAPQI, causes delayed harm. Option , depletion of endogenous antioxidants (glutathione), is correct-NAPQI, formed via CYP450 metabolism, overwhelms glutathione, leading to oxidative stress and hepatotoxicity. Option , hapten formation, occurs with some drugs but not acetaminophen's primary toxicity. Option , cytochrome C oxidase inhibition, is cyanide's mechanism, not acetaminophen's. Option , ischemia from reduced blood flow, isn't the issue-damage is metabolic. Option (E), gallbladder paralysis, is irrelevant. NAPQI's glutathione depletion disrupts detoxification, causing centrilobular necrosis, explaining the delayed presentation and justifying urgent treatment like N-acetylcysteine to replenish glutathione.

Correct Answer: C

Rationale: In the context of mild hyponatremia, which is a condition where there is a lower-than-normal concentration of sodium in the blood, treatment often involves administering intravenous normal saline infusion administered slowly. This helps to incrementally increase sodium levels in the blood while also ensuring proper hydration. Normal saline is preferred over other fluid solutions as it helps to maintain a stable electrolyte balance. In cases of severe hyponatremia or symptoms like seizures, more aggressive treatment may be necessary, but for mild cases like that described in the scenario, normal saline infusion is typically the appropriate choice.

Correct Answer: B

Rationale: Timolol and carteolol are available in an ophthalmic form of the drug for reduction of intraocular pressure in patients with open-angle glaucoma. A decrease in intraocular pressure would indicate it has been effective. Timolol can also be used to treat hypertension but an increase in blood pressure would indicate the drug was not effective. Reduced pulse rate and reduced angina would not be related to this drug, especially if it was given in ophthalmic form when very little of the drug is absorbed systemically.

Correct Answer: A

Rationale: The extraction ratio (ER = hepatic clearance / liver blood flow) quantifies first-pass metabolism's impact on bioavailability (F = 1 - ER), a true statement. It doesn't directly affect volume of distribution, which is a distribution parameter, so that's false. Oral morphine's bioavailability is ~20-30%, not exactly 15%, but close, though false per key. Phenytoin's extraction ratio is low, not high, due to capacity-limited metabolism. Lidocaine's high first-pass effect prevents oral efficacy, true. The ER formula is foundational in pharmacokinetics, predicting oral drug availability.