Zocor and grapefruit
Grapefuit juice is an inhibitor of an enzyme in the small intestine, which plays an important role in breaking down of various statins like zocor (also lipitor, mevacor). So grapefruit slows down the metabolization of zocor, resulting in a high level of zocor in the blood.
A high level of zocor is toxic, so patients taking zocor should avoid grapefruit or other grapefruit-containing products.
It is recommended that you don’t drink more than 1 quart of grapefruit-juice daily. Better not to drink at all grapefruit or other related products.
This effect of the grapefruit can persist up to 3 days, so you can not drink grapefruit juice in the morning and take zocor in the evening.