A nurse is reviewing a patient’s medications before administration. Which drug-to-drug interactions will most concern the nurse in a patient with a history of heart failure and a potassium level of 5.5 mEq/L?

Choice A reason: Drugs with toxic side effects, like chemotherapy agents, can affect multiple organs (e.g., liver, kidneys, heart). Monitoring organ function through lab tests (e.g., LFTs, creatinine) detects early toxicity, allowing timely intervention. Patient education on this ensures adherence and awareness, making this the most comprehensive and proactive approach.

Choice B reason: Ordering complete blood counts is relevant for drugs affecting bone marrow (e.g., chemotherapy), but it’s too narrow. Toxic drugs may impact other organs like the liver or kidneys, requiring broader monitoring (e.g., LFTs, renal panels). Focusing solely on blood counts misses other potential toxicities, making this choice incomplete.

Choice C reason: Discontinuing all medications is drastic and inappropriate without assessing the drug’s benefits versus risks. Many toxic drugs (e.g., methotrexate) are essential for treatment. Monitoring and managing side effects are preferred to maintain therapy efficacy while minimizing harm, making this choice clinically unsound.

Choice D reason: Waiting for symptoms before follow-up risks missing subclinical toxicity, as many drug-induced organ damages (e.g., hepatotoxicity) are asymptomatic initially. Proactive monitoring of organ function through lab tests is essential to detect issues early, making this reactive approach inadequate for managing drugs with known toxic effects.

Choice A reason: Hyperthyroidism involves elevated T3 and T4 with low TSH due to excessive thyroid hormone production. The patient’s low T3/T4 and high TSH indicate reduced thyroid activity, not overactivity, as the pituitary increases TSH to stimulate the underactive thyroid, making this choice incorrect.

Choice B reason: Hypothyroidism is characterized by low T3 and T4 levels due to underactive thyroid function, prompting the pituitary to secrete more TSH to stimulate hormone production. This matches the patient’s lab results (low T3/T4, high TSH), often seen in primary hypothyroidism, making this the correct choice.

Choice C reason: Thyroid cancer may alter thyroid function but typically doesn’t present with consistently low T3/T4 and high TSH. It’s more likely to cause nodules or abnormal growths, not this specific hormonal pattern, which aligns with hypothyroidism, making this choice less likely.

Choice D reason: Pituitary adenoma causing secondary hypothyroidism would lower TSH, T3, and T4 due to impaired pituitary function. High TSH with low T3/T4 suggests primary thyroid failure, not pituitary dysfunction, making this choice incorrect for the patient’s hormonal profile.