Oncology Certified Nurse (OCN) Nursing Practice Test

When do Carbo reactions typically occur during chemotherapy cycles?

1. After 1st cycle

2. After 6th cycle, mid-cycle

3. After 3rd cycle

4. After 10th cycle

The correct answer is: After 6th cycle, mid-cycle

Carbo reactions, which refer to reactions associated with carboplatin-based chemotherapy regimens, typically manifest after completion of certain cycles of treatment. The reasoning behind selecting the specific choice of occurring after the 6th cycle, particularly mid-cycle, is grounded in the pharmacodynamics and cumulative toxicity of the drug. Carboplatin, a widely used platinum-based chemotherapy agent, may lead to side effects that become more pronounced with multiple cycles of treatment. This includes an increase in myelosuppression, particularly thrombocytopenia, which is the reduction in platelets that can lead to increased risk of bleeding. While reactions can occur after differing cycles depending on individual patient factors, they are often observed to have a notable increase or to become clinically significant after several cycles due to the additive effects of the drug on the bone marrow. The selection of mid-cycle after the 6th cycle reflects a timing when patients are well into their treatment protocol, during which cumulative toxicities may present themselves more frequently. Monitoring and management of such reactions is crucial in the ongoing care of patients undergoing chemotherapy, as it impacts their treatment plan and overall health.