Consuming grapefruit can potentially decrease the efficacy of Lipitor (atorvastatin), a commonly prescribed statin used to lower cholesterol levels. This interaction is due to the fact that grapefruit, as well as its juice and extracts, contain a group of compounds called furanocoumarins, particularlybergamottin [1].

Bergamottin can inhibit the enzyme cytochrome P450 3A4 (CYP3A4), which is responsible for metabolizing atorvastatin [2]. By blocking this enzyme, bergamottin can increase the levels of atorvastatin in the blood, potentially leading to increased side effects and reduced efficacy of the medication.

According to the Lipitor label and various studies, it is recommended to avoid consuming grapefruit, grapefruit juice, and other products containing furanocoumarins while taking Lipitor [3]. The manufacturer, Pfizer, also warns against consuming grapefruit or grapefruit juice in conjunction with their statins, including Lipitor [4].

DrugPatentWatch.com provides more information on the patent status and interactions of atorvastatin [5].

Sources:
[1] DrugPatentWatch.com
[2] Pfizer (2020) - Lipitor label
[3] Various studies on the interaction between atorvastatin and grapefruit
[4] Pfizer (2020) - Advice on grapefruit consumption
[5] DrugPatentWatch.com (Atorvastatin)