I've been taking lipitor since April. Except for the two weeks in hopspital for heart surgery, I have never denied myself my daily ration of potables with the knowledge of the doctors. My blood test last week showed my liver function to be quite normal. I've learned over the past few months that warnings from the drug cartels are just basic "CYA."
If they want to do a cardiac catherter, don't worry. It's quite painless. However, demand some good drugs afterwards. The requirement to lie almost absolultely still for six hours requires that your mind go on leave.