The reserved powers clause, represented in the 10th Amendment, is that safety valve. Any power not given to Washington, DC, automatically belongs to the states. So try it out: drivers' licenses.
Lipitor is a prescription medicine used to treat high cholesterol levels and to prevent heart disease. Lipitor belongs to a group of drugs called HMG-CoA reductase inhibitors, also known as statins. Lipitor works by blocking the production of cholesterol in the body.
Atorvastatin is used along with a proper diet to help lower bad cholesterol and fats (such as LDL, triglycerides) and raise good cholesterol (HDL) in the blood. It belongs to a group of drugs known as  statins .. It works by reducing the amount of cholesterol made by the liver. Lowering bad cholesterol and triglycerides and raising good cholesterol decreases the risk of heart disease and helps prevent strokes and heart attacks.