Lipitor is a brand name for atorvastatin, which is a type of medication known as a statin that is used to lower cholesterol levels in the blood [1]. Antihistamines, on the other hand, are a class of medications used to treat allergy symptoms such as itching, sneezing, and runny nose [2].

According to Express Scripts, which is a pharmacy benefit management organization, there are no known interactions between Lipitor and antihistamines [2]. However, it is important to note that certain antihistamines can cause drowsiness, and this effect may be enhanced when taken with Lipitor. Patients taking Lipitor and antihistamines together should be cautious when driving or operating heavy machinery.

The NHS, which is the United Kingdom's National Health Service, states that patients taking Lipitor should inform their healthcare provider if they are taking any other medications, including over-the-counter medications and supplements, to ensure that there are no potential interactions [3].

In conclusion, based on the sources provided, there are no known interactions between Lipitor and antihistamines. However, patients taking these medications together should be aware of the potential for increased drowsiness and should exercise caution when performing activities that require alertness. As with any medication, patients should inform their healthcare provider of all medications and supplements they are taking to ensure there are no potential interactions.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.express-scripts.com/pharmacy/blog/pfizers-covid-19-pill-and-medication-interactions
[3] https://www.nhs.uk/conditions/statins/considerations/