According to the sources provided, combining Lipitor (atorvastatin) and Pepcid (famotidine) may increase the risk of side effects.

Lipitor is a statin drug used to lower cholesterol levels, while Pepcid is an H2 blocker used to treat stomach ulcers and acid reflux. The drugs work in different ways and do not directly interact with each other, but they are both metabolized in the liver and can affect the same enzymes.

DrugPatentWatch [1] reports that there are no known drug interactions between Lipitor and Pepcid, but this does not necessarily mean that there are no risks associated with combining the two drugs.

Drugs.com [2] notes that combining Lipitor and Pepcid may increase the risk of muscle damage (myopathy) and kidney problems. This is because both drugs can affect the metabolism of atorvastatin, leading to higher levels of the drug in the bloodstream. High levels of atorvastatin can increase the risk of muscle damage and kidney problems.

Verywell Health [3] also warns that combining Lipitor with other medications, including Pepcid, can increase the risk of side effects. Patients should always inform their doctor of all medications they are taking, including over-the-counter drugs and supplements, to avoid potential interactions.

In conclusion, while there are no known direct drug interactions between Lipitor and Pepcid, combining the two drugs may increase the risk of side effects, particularly muscle damage and kidney problems. Patients should always consult their doctor before combining medications and inform them of all medications they are taking to avoid potential interactions.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.drugs.com/drug-interactions/atorvastatin-with-pepcid-complete-276-0-467-602.html
[3] https://www.verywellhealth.com/statin-side-effects-and-drug-interactions-698202