Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels in the blood. Allergy medications, on the other hand, are used to treat allergies and their symptoms.

According to the Mayo Clinic [2], the most common side effects of atorvastatin include muscle and joint pain, diarrhea, and constipation. These side effects are usually mild and go away on their own. However, some people may experience more serious side effects such as liver problems, muscle damage, and allergic reactions.

The NHS [3] notes that some allergy medications, such as antihistamines, can interact with atorvastatin and increase the risk of side effects. It is important to talk to a doctor or pharmacist before taking any new medications, including allergy medications, while on atorvastatin.

Drug Patent Watch [1] does not provide specific information on the interaction between atorvastatin and allergy medications. However, it is important to note that all medications have the potential to interact with each other and cause side effects.

In summary, the most common side effects of atorvastatin include muscle and joint pain, diarrhea, and constipation. Allergy medications can potentially interact with atorvastatin and increase the risk of side effects. It is important to talk to a doctor or pharmacist before taking any new medications while on atorvastatin.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/side-effects/drg-20067003
[3] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/