Sometimes Lipitor can cause mild elevations in liver enzymes, such as AST and ALT. Usually, this is just monitored. If the enzymes increase to 3 times the upper limit of normal, then the medication is usually stopped. Having an AST of 45 is not too worrisome, but just make sure your doctor rechecks it in about 3 months.
What is the problem: Lipitor. Lipitor and other statins have a long list of adverse health problems including liver damage, kidney failure, heart failure, cataracts and diabetes.