Final answer:
The adverse effect of atorvastatin indicated by a laboratory report would be elevated liver enzymes, signaling potential liver damage, which is a concern when administering statins. The correct option is A).
Step-by-step explanation:
A nurse who is evaluating a laboratory report for a client taking atorvastatin should be aware that an adverse effect of this medication would be indicated by elevated liver enzymes. Atorvastatin belongs to the class of drugs known as statins, which are inhibitors of the enzyme HMG-CoA reductase. Their primary function is to reduce the synthesis of cholesterol in the body. While increased HDL levels, decreased triglyceride levels, and normal cholesterol levels are usually desired outcomes when taking atorvastatin, elevated liver enzymes can signal potential liver damage, which is a concerning adverse effect of this medication.