A patient has a new prescription for a blood pressure medication that may cause him to feel dizzy during the first few days of therapy. Which is the best nursing diagnosis for this situation?

Correct Answer: B

Rationale: Dizziness is a common side effect of many blood pressure medications, particularly during the initial days of therapy. This side effect increases the patient's risk of falls or other injuries, especially in elderly patients or those with mobility issues. The nursing diagnosis 'Risk for injury' is the most appropriate because it directly addresses the potential harm caused by dizziness. While 'Activity intolerance' and 'Self-care deficit' may be relevant in some cases, they do not specifically address the immediate risk posed by dizziness. 'Disturbed body image' is unrelated to this scenario. Therefore, 'Risk for injury' is the best diagnosis to guide nursing interventions, such as monitoring the patient and educating them on safety measures.

Correct Answer: B

Rationale: Steady-state concentration is reached after 4-5 half-lives, when drug input equals output. Digoxin's half-life is 40 hours (1.67 days). Four half-lives is 4 × 40 = 160 hours (6.67 days), and five is 200 hours (8.33 days). Over 90% steady state occurs around 4 half-lives, roughly 6-7 days. Two days (48 hours) is only ~1.2 half-lives, far too short. Ten days (~6 half-lives) exceeds 90%, but 7 days (~4.2 half-lives) aligns with >90% (e.g., 94% at 4 half-lives). Fourteen or 18 days overshoot unnecessarily. Seven days balances precision and practicality, guiding digoxin dosing timelines in heart failure or arrhythmias.

Correct Answer: D

Rationale: Volume of distribution (Vd) is a pharmacokinetic parameter reflecting the extent a drug distributes into body tissues relative to plasma. It's not always a real volume, as it can exceed total body water (e.g., for lipophilic drugs), making that statement false. The second option is nonsensical due to unclear phrasing, but likely intends a ratio that's incorrectly stated. The third option reverses the correct formula and is also gibberish. The accurate definition is the amount of drug in the body divided by its concentration in plasma (Vd = Dose / Cp), which quantifies how widely a drug disperses. This isn't about area under the curve (AUC) or dose, as some might confuse with clearance. Understanding Vd is crucial for dosing adjustments, especially for drugs with high tissue affinity, where a large Vd indicates extensive distribution beyond plasma, impacting therapeutic strategies.

Correct Answer: A

Rationale: Terazosin, an alpha-1 adrenergic blocker, treats both hypertension and benign prostatic hyperplasia (BPH) by relaxing smooth muscle in blood vessels and the prostate, lowering blood pressure and easing urinary symptoms. Sildenafil, used for erectile dysfunction, doesn't address hypertension or BPH and may cause hypotension, making it unsuitable here. Finasteride, a 5-alpha reductase inhibitor, shrinks the prostate for BPH but has no effect on blood pressure, missing the dual need. Tamsulosin, another alpha-1 blocker, relieves BPH symptoms but isn't typically used for routine hypertension management and risks severe hypotension. Terazosin's dual action makes it uniquely safe and effective, addressing both conditions without exacerbating either, unlike the others, which lack hypertensive benefits or pose risks in this context.

Correct Answer: C

Rationale: A loading dose rapidly achieves therapeutic levels, followed by a lower maintenance dose, a standard approach explained clearly here. Half-life isn't shortened-it's about concentration. ‘Always' oversimplifies. Side effect reduction isn't the goal-efficacy is. The larger initial dose's purpose reassures the patient, aligning with pharmacokinetic principles for quick action.