A nurse is caring for a client who is taking lovastatin and has a new prescription for ezetimibe to lower cholesterol levels. Which of the following laboratory values should the nurse monitor?

Choice A rationale Calcium levels are primarily regulated by parathyroid hormone and calcitonin and are essential for bone health and muscle function. Neither lovastatin nor ezetimibe directly impacts calcium metabolism to a degree that requires routine monitoring of serum calcium levels. Calcium monitoring is not a primary concern for these lipid-lowering medications. Choice B rationale Creatinine clearance is a measure of renal function, reflecting the kidney's ability to filter waste products from the blood. While some medications can affect kidney function, lovastatin and ezetimibe do not typically have significant nephrotoxic effects that necessitate routine monitoring of creatinine clearance unless pre-existing renal impairment is present. Choice C rationale Thyroid stimulating hormone (TSH) is produced by the pituitary gland and regulates thyroid hormone production. There is no direct pharmacological mechanism by which lovastatin or ezetimibe would significantly alter thyroid function or TSH levels. Therefore, TSH monitoring is not a standard requirement for these lipid-lowering therapies. Choice D rationale Both lovastatin (a statin) and ezetimibe can, albeit rarely, cause liver dysfunction, including elevated liver enzymes. Alanine aminotransferase (ALT) is a specific indicator of hepatocellular injury. Monitoring ALT is crucial to detect potential drug-induced hepatotoxicity, particularly with combination therapy, ensuring early intervention if liver damage occurs. Normal ALT is typically 7-55 U/L.