Lipitor is a brand name for the drug atorvastatin, which is a type of statin used to lower cholesterol levels in the body. Grapefruit juice can interact with certain medications, including statins, by inhibiting the enzymes responsible for breaking down the drug in the liver. This can lead to higher levels of the drug in the bloodstream and increase the risk of side effects.

According to the sources provided, drinking grapefruit juice can indeed affect Lipitor dosage. Health Harvard notes that grapefruit juice can increase the concentration of Lipitor in the bloodstream, which can lead to a higher risk of side effects such as muscle pain and liver damage [2]. The article also suggests that other citrus fruits, such as Seville oranges and limes, may have a similar effect [2].

Verywell Health recommends avoiding grapefruit and grapefruit juice while taking Lipitor or other statins, as the interaction can last for up to 24 hours after consumption [3]. The article notes that the effect of grapefruit juice on statins can vary from person to person and can depend on factors such as age, gender, and overall health [3].

Drug Patent Watch provides information on the patent status of Lipitor but does not directly address the interaction between grapefruit juice and the drug [1].

In conclusion, drinking grapefruit juice can affect Lipitor dosage by increasing the concentration of the drug in the bloodstream. It is recommended to avoid grapefruit and grapefruit juice while taking Lipitor or other statins to reduce the risk of side effects.

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