A nurse is reviewing laboratory data for a client who is taking simvastatin to correct plasma lipid levels. Which of the following findings should the nurse identify as an adverse effect of this therapy?

Choice A rationale Simvastatin is a HMG-CoA reductase inhibitor, or statin, that blocks cholesterol synthesis in the liver. A potential adverse effect is hepatotoxicity, which is indicated by elevated liver enzymes like alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The normal ALT range is 7 to 56 units/L. Monitoring these enzymes is crucial to detect liver injury. Choice B rationale Troponin T is a protein released from cardiac muscle when it is damaged. An elevated troponin T level is a specific and sensitive indicator of myocardial injury, such as a myocardial infarction. It is not directly associated with the pharmacological action or known adverse effects of simvastatin, which primarily targets lipid metabolism in the liver. Choice C rationale An elevated white blood cell (WBC) count, or leukocytosis, is a general indicator of an inflammatory or infectious process in the body. While a variety of medications can affect WBC counts, simvastatin is not typically known to cause leukocytosis. The normal WBC count is 4,500 to 11,000 cells/mm³. Choice D rationale Thyroid-stimulating hormone (TSH) is produced by the pituitary gland to regulate thyroid hormone production. An elevated TSH level suggests hypothyroidism, a condition where the thyroid gland is underactive. Simvastatin does not directly affect the hypothalamic-pituitary-thyroid axis, and an elevated TSH is not a recognized adverse effect.