What health maintenance action should be taken when increasing a patient's methotrexate dose?

When increasing a patient's methotrexate dose, monitoring is crucial due to the drug's potential for harmful effects, particularly on bone marrow and renal function. Checking a complete blood count (CBC) and blood chemistry profile within six weeks after the dosage increase is essential because methotrexate can lead to cytopenias, where blood cell counts (such as hemoglobin, white blood cells, and platelets) may drop, along with impacts on renal functions indicated by changes in creatinine and electrolytes. This proactive monitoring allows for timely detection of any adverse effects, enabling prompt medical intervention if necessary.

Other health maintenance actions may be relevant for different scenarios involving methotrexate therapy. However, they do not directly relate to the immediate need for monitoring after a dose increase. For instance, while screening for tuberculosis is important before starting methotrexate due to its immunosuppressive nature, it is not specifically required when just increasing the dose in a patient already on the medication. Thus, the focus on immediate laboratory monitoring (the correct answer) helps ensure the patient remains safe and that any potential side effects can be addressed quickly.