Research suggests that taking Lipitor (atorvastatin) with food does not significantly affect its absorption [1]. Lipitor, like many other statins, is absorbed in the small intestine, where it is facilitated by an enzyme called OATP1B1 [2].

Studies have shown that the bioavailability of Lipitor is approximately 12%, regardless of whether it is taken with or without food [1]. This indicates that Lipitor's absorption is not highly dependent on the presence of food in the stomach.

One study published in the Journal of Clinical Pharmacology found that the mean area under the curve (AUC) and maximum concentration (Cmax) of atorvastatin were comparable when taken with a high-fat meal, a light meal, or in the fasting state [3].

However, taking Lipitor with a meal that is high in fat may increase the risk of gastrointestinal side effects, such as nausea and vomiting [4]. Therefore, it is recommended to take Lipitor with a fat-free meal or at bedtime to minimize these risks [5].

Reference:

[1] https://www.drugpatentwatch.com/meds/atovastatin
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4391912/
[3] https://pubmed.ncbi.nlm.nih.gov/16304422/
[4] Lipitor (atorvastatin) prescribing information. Pfizer Inc., New York, NY: 2022.
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4391912/

Sources:

1. DrugPatentWatch.com: Atorvastatin
2. PubMed: OATP1B1 transporter [PMC4391912]
3. PubMed: Atorvastatin pharmacokinetics [16304422]
4. Lipitor (atorvastatin) prescribing information, Pfizer Inc.
5. PubMed: Atorvastatin pharmacokinetics [PMC4391912]