A 60-year-old woman comes to the physician because she recently was diagnosed with non-small cell lung carcinoma and she wants to discuss possible treatment options. She tells the physician that she is concerned about the possible adverse effects of chemotherapy. The physician says that serious toxicity caused by antineoplastic drugs is seen in the bone marrow. Which of the following best explains this finding?

Correct Answer: A

Rationale: Bone marrow toxicity (e.g., myelosuppression) from chemotherapy occurs because marrow cells divide rapidly (A), making them highly susceptible to drugs targeting cell division (e.g., alkylating agents, antimetabolites). Specific targets apply to some drugs (e.g., imatinib), not most. ‘Used to prevent’ is unclear, nucleated cells aren’t the sole target (red cells lack nuclei), vascularity (E) aids delivery but isn’t the reason, and lipid solubility (F) varies by drug.

Correct Answer: C

Rationale: The correct answer is C: Lifestyle modifications. This is because lifestyle modifications, such as healthy diet and regular exercise, are the first line therapy for hyperlipidemia. These interventions can help lower cholesterol levels without the need for medication. Bile Acid Sequestrants (A) and Niacin (D) are less commonly used due to side effects and limited efficacy compared to statins. Statin Therapy (B) may be considered as second-line therapy if lifestyle modifications are not sufficient to reach target lipid levels.

Correct Answer: A

Rationale: The correct answer is A because warfarin inhibits the synthesis of vitamin K dependent clotting factors, including Factors II, IX, and X, as well as proteins C and S. These specific factors are crucial for the blood clotting cascade. Factors VII, VIII, and XII are not directly affected by warfarin, making options B and C incorrect. Choice D is incorrect as it includes Factor VII, which is not a vitamin K dependent clotting factor. In summary, choice A is correct because it includes all the relevant vitamin K dependent clotting factors that are impacted by warfarin's mechanism of action.

Correct Answer: D

Rationale: The correct answer is D: ACE inhibitors reduced preload. ACE inhibitors work by inhibiting the conversion of angiotensin I to angiotensin II, which leads to vasodilation and reduced preload on the heart. This results in decreased workload for the failing heart, improving its function. Explanation for why other choices are incorrect: A: ACE inhibitors do not increase aldosterone. In fact, they decrease aldosterone levels by inhibiting angiotensin II, which stimulates aldosterone release. B: ACE inhibitors do not increase vascular resistance. They actually reduce vascular resistance by blocking the vasoconstrictive effects of angiotensin II. C: ACE inhibitors do not decrease cardiac output. They may initially cause a slight decrease due to reduced preload, but overall they improve cardiac output by reducing the workload on the heart.

Correct Answer: A

Rationale: The correct answer is A because lithium can affect thyroid function, leading to hypothyroidism. Monitoring thyroid levels is crucial to detect any abnormalities early and adjust treatment accordingly. Choice B, C, and D are incorrect as they do not address the specific reason for requiring regular blood tests in a patient prescribed lithium for bipolar disorder.