An older adult is diagnosed with HIV and prescribed zidovudine (Retrovir). Which diagnostic test is helpful in assessing side effects?

The most relevant diagnostic test for assessing the side effects of zidovudine (Retrovir) is a complete blood count (CBC). Zidovudine is known to potentially cause bone marrow suppression, leading to conditions such as anemia, leukopenia, and thrombocytopenia. A CBC will help monitor the levels of red blood cells, white blood cells, and platelets in the patient's blood, allowing healthcare providers to identify any adverse effects related to blood cell production.

Each of the other tests mentioned does not effectively assess the specific side effects associated with zidovudine. Hemoglobin A1c provides information about long-term blood sugar control and is more relevant for diabetes management. An immunodeficiency panel mainly assesses the immune status of the patient rather than the direct side effects of medication. Serum glucose testing focuses on current blood sugar levels, which is not pertinent in monitoring the side effects of zidovudine. By utilizing a CBC, clinicians can effectively manage and address any adverse hematological effects that may arise during treatment.