A nurse is reviewing the laboratory results of a client who is taking simvastatin. Which of the following laboratory values should the nurse report to the provider?

Simvastatin is an HMG-CoA reductase inhibitor used to treat dyslipidemia by reducing hepatic cholesterol synthesis. While effective for cardiovascular prophylaxis, it carries risks of hepatotoxicity and myopathy. Clinical monitoring focuses on liver function tests and markers of muscle integrity to detect early signs of statin-induced organ injury. Rationale: A. Decreased creatine kinase (CK) is not a finding of clinical concern; however, increased CK would be highly significant. Elevated CK levels indicate muscle breakdown or rhabdomyolysis, which is a rare but severe side effect of statin therapy. A low or normal CK level suggests that the medication is not currently causing significant damage to the client's skeletal muscle tissue. B. Increased alkaline phosphatase is a marker of potential liver injury or biliary obstruction and must be reported to the provider immediately. Since simvastatin is processed by the liver, it can cause asymptomatic elevations in liver enzymes or, in rare cases, drug-induced hepatitis. The nurse must monitor for jaundice and upper quadrant pain when these laboratory values are elevated. C. Increased HDL is a positive therapeutic outcome of simvastatin therapy and does not need to be reported as an adverse finding. High-density lipoprotein is the "good" cholesterol that aids in the transport of cholesterol away from the arteries. An increase in this value indicates that the medication and lifestyle changes are successfully reducing the client's overall cardiovascular risk profile. D. Decreased HbA1c is generally a favorable finding, as it indicates improved long-term glucose control. Statins have actually been associated with a slight increase in HbA1c and blood glucose levels in some patients, potentially increasing the risk of diabetes. Therefore, a decrease would not be considered a medication-related adverse effect that requires urgent notification to the healthcare provider.