When taking Digoxin, low levels of what can cause toxicity?

Correct Answer: A

Rationale: When taking Digoxin, low levels of potassium can cause toxicity because digoxin competes with potassium for binding sites on the sodium-potassium pump in cardiac cells. Low potassium levels can lead to increased binding of digoxin to the pump, resulting in increased intracellular calcium levels and an increased risk of digoxin toxicity, including arrhythmias. Therefore, monitoring and maintaining adequate potassium levels are crucial in patients taking digoxin to prevent toxicity.

Correct Answer: C

Rationale: Buprenorphine is a partial agonist at opioid receptors, providing analgesia with a ceiling effect, reducing risk of respiratory depression.

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: 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: To evaluate the medical effectiveness of Metformin, it is essential to monitor serum glucose levels, as Metformin is commonly used to treat type 2 diabetes by decreasing glucose production in the liver and increasing insulin sensitivity in peripheral tissues. Monitoring serum electrolytes, ketones, blood pH, lactate, and pyruvate levels is also important because Metformin can potentially cause lactic acidosis, especially in patients with kidney or liver impairment. By assessing these parameters, healthcare providers can gauge the efficacy and safety of Metformin therapy. Checking for resolution of hypothyroidism and hormone normalization is not directly related to evaluating Metformin's effectiveness. Pain reduction and patient alertness are also not the primary indicators for assessing the medical effectiveness of Metformin in managing diabetes.