A client taking atorvastatin develops an increased serum creatine phosphokinase (CK) level. The nurse should assess the client for the onset of which problem?

Rationale: A. Peripheral edema: While edema can occur with certain cardiovascular or renal conditions, it is not a common adverse effect of atorvastatin. Elevated CK levels specifically point to muscle breakdown rather than fluid retention. B. Excessive bruising: Bruising would suggest platelet dysfunction or coagulation abnormalities. Atorvastatin is not strongly associated with bleeding tendencies, so this finding would not directly correlate with an elevated CK. C. Nausea and vomiting: Gastrointestinal discomfort, including nausea, can occur with atorvastatin, but it is not the primary concern when CK levels are elevated. Elevated CK levels are more indicative of muscle injury than digestive upset. D. Muscle tenderness: Increased serum CK signals muscle damage or rhabdomyolysis, a serious complication of statins. Assessing for muscle tenderness, weakness, or pain helps identify statin-induced myopathy early.