Lipitor, also known as atorvastatin, is a medication that is used to lower cholesterol levels in the blood. The drug works by blocking an enzyme that is responsible for producing cholesterol in the liver [1]. According to a study published in the National Center for Biotechnology Information, atorvastatin has been found to have analgesic effects, which means that it can reduce pain in some patients [2]. However, the study did not investigate how Lipitor affects the efficacy of painkillers.

It is important to note that the expiration date of a medication does not necessarily mean that it is no longer effective or safe to use. According to Harvard Health Publishing, most medications are still effective and safe to use for up to a year after their expiration date, but it is always best to check with a healthcare provider before using any expired medication [3].

In conclusion, while atorvastatin has been found to have analgesic effects, there is no evidence to suggest that it affects the efficacy of painkillers. It is important to follow proper medication guidelines and consult with a healthcare provider before using any medication, including expired medication.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3469950/
[3] https://www.health.harvard.edu/staying-healthy/drug-expiration-dates-do-they-mean-anything