A client is taking lovastatin (Mevacor). Which serum level is most important for the nurse to monitor?

• A. Blood urea nitrogen
• B. Complete blood count
• C. Cardiac enzymes
• D. Liver enzymes

Answer: (C)

Lovastatin can affect the liver, so the most important lab to monitor is liver function. Checking liver enzymes (typically ALT and AST) before starting therapy and then periodically during treatment helps detect hepatotoxicity early, allowing dose adjustments or discontinuation if elevations occur. Cardiac enzymes are used to diagnose heart muscle injury, not to track routine statin therapy. BUN and CBC aren’t specific indicators of statin safety, though they can be useful for other reasons. Muscle symptoms may prompt checking creatine kinase if myopathy or rhabdomyolysis is a concern, especially with certain drug interactions.