A 57-year-old patient, living at home, has severe pain due to a metastatic carcinoma that is being managed with fentanyl, delivered transdermally from a patch. He should also be taking, or at least have on hand

Correct Answer: B

Rationale: Fentanyl, a potent opioid, effectively manages severe cancer pain via transdermal delivery, but constipation is a universal side effect due to mu receptor activation in the gut, reducing motility. Docusate, a stool softener, prevents and treats this by easing bowel movements, essential for patient comfort and compliance. Apomorphine, a dopamine agonist, treats Parkinson's off-periods, irrelevant here. Loperamide, an antidiarrheal, worsens constipation. Morphine duplicates fentanyl's action, unnecessary with a patch. Naloxone reverses overdose, useful in emergencies but not routine. Given fentanyl's chronic use, proactively managing constipation with docusate is critical, as it mitigates a predictable, distressing side effect without altering pain control.

Correct Answer: C

Rationale: Dantrolene sodium is associated with hepatotoxicity, making liver function tests essential for monitoring adverse effects. Elevated liver enzymes (ALT, AST) may indicate liver damage, requiring discontinuation of the drug. Blood urea nitrogen and creatinine are used to assess kidney function, while triglyceride levels are unrelated to dantrolene's primary adverse effects. Regular monitoring of liver function is critical to ensure patient safety during treatment.

Correct Answer: A

Rationale: A blood pressure of 88/62 mm Hg indicates hypotension, which is a contraindication for nitrates and nitrites use. Nitrates and nitrites are vasodilators that can further lower blood pressure, potentially leading to severe hypotension and cardiovascular collapse in a patient with already low blood pressure. Therefore, caution should be exercised in administering nitrates and nitrites to a patient with hypotension. In this case, the presence of severe chest pain may be indicative of a myocardial infarction, which would typically warrant the consideration of nitroglycerin (a nitrate) administration for chest pain relief. However, in the presence of hypotension, alternative treatment options may need to be considered first to stabilize the blood pressure before nitrate administration.

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: Heparin, an anticoagulant, prolongs clotting via antithrombin, monitored by aPTT to ensure therapeutic range (1.5-2.5 times normal) and prevent bleeding or clotting risks. PT/INR (choices A, C) track warfarin, not heparin. Platelet count matters for heparin-induced thrombocytopenia but isn't the primary pre-dose check'baseline and periodic counts suffice. aPTT directly reflects heparin's effect, guiding dosing adjustments, especially in acute settings like DVT or PE. Checking it ensures safety, as excessive anticoagulation causes hemorrhage, while under-dosing fails therapy. This aligns with heparin's rapid action and short half-life, making B the critical lab value to verify before administration.

Correct Answer: D

Rationale: Amlodipine belongs to the pharmacologic class of calcium channel blockers. It works by inhibiting the influx of calcium ions into smooth muscle cells, leading to vasodilation and lower blood pressure. This medication is commonly used to treat hypertension (high blood pressure) and certain types of angina (chest pain). It is not a beta blocker, 5-HT3 antagonist, or nonopioid analgesic.

Correct Answer: D

Rationale: Pharmacological classification groups drugs by mechanism-anticoagulants influence clotting by inhibiting factors like thrombin, a precise definition. Anti-anginal and antihypertensive describe therapeutic effects, not mechanisms. Calcium channel blockers' action is mechanistic but less broad than clotting's systemic impact. Anticoagulants' specific role in coagulation reflects accurate classification understanding, key for pharmacology learning.

Correct Answer: B

Rationale: The kidneys filter approximately 130 mL/min of protein-free plasma, which is the glomerular filtration rate in healthy adults.