I read on line that it is safe to drink red grapefruit juice if your taking pravachol, (pravastatin) is it?

Grapefruit Interacti: Yes. Pravachol (pravastatin) activity is not affected by grapefruit.

In moderation: Safer to eat red grapefruit, as you are less likely to eat 6, 12, 20, etc, than drink 1/2 gallon, which might cause drug metabolism issue with certain meds. Intermittent use (/eating or drinking) allows time for liver to process the meds and other things presented to it.