Lipitor is a brand name for the drug atorvastatin, which is used to treat high cholesterol levels in the blood. According to the sources provided, there is no indication that Lipitor can cause allergic reactions with antihistamines. However, it is always important to consult with a healthcare professional before taking any medication, especially if you are already taking other medications or have a history of allergies.

DrugPatentWatch [1] provides information on the patent status of Lipitor, but does not mention any information on allergic reactions or interactions with antihistamines.

The FDA [2] warns about the potential for photosensitivity reactions when taking certain medications, including some cholesterol-lowering drugs like Lipitor. These reactions can cause skin rashes or other allergic-type reactions when exposed to sunlight or other sources of ultraviolet light. However, this information is not directly related to interactions with antihistamines.

The American Heart Association [3] provides information on medication interactions, including the potential for drug interactions with antihistamines. While Lipitor is not specifically mentioned, it is important to note that some medications can interact with antihistamines and cause side effects such as drowsiness or dizziness.

In summary, based on the sources provided, there is no evidence to suggest that Lipitor can cause allergic reactions with antihistamines. However, it is always important to consult with a healthcare professional before taking any medication, especially if you are already taking other medications or have a history of allergies.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.fda.gov/drugs/special-features/sun-and-your-medicine
[3] https://www.heart.org/en/health-topics/consumer-healthcare/medication-information/medication-interactions-food-supplements-and-other-drugs