Lipitor is a brand name for the drug atorvastatin, which belongs to a class of drugs called statins. Statins are commonly used to lower cholesterol levels in the blood. Grapefruit juice can interact with certain medications, including statins, and cause adverse effects. According to GoodRx [2], you should avoid consuming grapefruit or grapefruit juice while taking Lipitor, as it can increase the risk of side effects. Health Harvard [3] also recommends avoiding grapefruit juice while taking statins, as it can increase the concentration of the drug in the blood, leading to an increased risk of side effects. Drug Patent Watch [1] does not provide specific information on how long one should wait after taking Lipitor to drink grapefruit juice. However, it is generally recommended to avoid grapefruit juice altogether while taking Lipitor to avoid any potential interactions. If you have any concerns or questions about your medication, it is best to consult with your healthcare provider.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.goodrx.com/classes/statins/why-cant-i-have-grapefruit-with-my-statin
[3] https://www.health.harvard.edu/heart-health/grapefruit-juice-and-statins