Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the body [1]. Grapefruit juice is known to interact with certain medications, including statins like Lipitor [2]. According to the sources provided, grapefruit juice can increase the concentration of Lipitor in the bloodstream, leading to a higher risk of side effects [2][3]. This is because grapefruit juice contains compounds that inhibit the enzymes responsible for breaking down Lipitor in the liver [3]. As a result, Lipitor may stay in the body longer and at higher concentrations than intended, increasing the risk of side effects such as muscle pain, liver damage, and kidney problems [2][3]. Therefore, it is generally recommended to avoid grapefruit juice while taking Lipitor [2][3]. Patients should consult their healthcare provider for specific recommendations regarding the use of Lipitor and grapefruit juice [2][3].

Sources:
[1] DrugPatentWatch. (n.d.). Lipitor. Retrieved from https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] Verywell Health. (2021, January 29). Can I Take Lipitor or Zocor With Grapefruit Juice? Retrieved from https://www.verywellhealth.com/can-i-take-lipitor-or-zocor-with-grapefruit-juice-1124045
[3] Harvard Health Publishing. (2017, June). Grapefruit juice and statins. Retrieved from https://www.health.harvard.edu/heart-health/grapefruit-juice-and-statins