Which of the following is NOT a common example of a statin?

Statins are a class of lipid-lowering medications primarily used to reduce cholesterol levels in the blood, particularly low-density lipoprotein (LDL) cholesterol. The common examples of statins include atorvastatin, simvastatin, and rosuvastatin, which all function by inhibiting the enzyme HMG-CoA reductase, key in cholesterol synthesis in the liver.

Niacin, on the other hand, is not a statin; it is classified as a B-vitamin and has lipid-altering effects, but it works through a different mechanism. Niacin can raise high-density lipoprotein (HDL) cholesterol and lower triglycerides, but it does not inhibit HMG-CoA reductase like statins do. Thus, identifying niacin as not belonging to the statin category is correct, as it is fundamentally different in its pharmacological action and classification.