Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels in the blood. Grapefruit juice is known to interact with some medications, including some statins like Lipitor. According to Health Harvard [2], grapefruit juice can increase the level of Lipitor in the bloodstream, which can lead to an increased risk of side effects. The article recommends avoiding grapefruit juice while taking Lipitor.

Verywell Health [3] also advises against consuming grapefruit juice while taking Lipitor, as it can increase the risk of side effects. The article notes that grapefruit juice can interfere with the body's ability to break down Lipitor, leading to higher levels of the drug in the bloodstream.

Drug Patent Watch [1] provides information on the patent status of Lipitor, but does not offer any information on the safety of adjusting Lipitor dosage with grapefruit juice.

In conclusion, it is not safe to adjust Lipitor dosage with grapefruit juice. Grapefruit juice can increase the level of Lipitor in the bloodstream, leading to an increased risk of side effects. Therefore, it is recommended to avoid consuming grapefruit juice while taking Lipitor.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.health.harvard.edu/heart-health/grapefruit-juice-and-statins
[3] https://www.verywellhealth.com/can-i-take-lipitor-or-zocor-with-grapefruit-juice-1124045