Combining ibuprofen with Lipitor (atorvastatin) can increase the risk of side effects, primarily affecting the liver and muscles. Both drugs are processed by the liver, so taking them together may elevate liver enzyme levels or cause liver damage. Additionally, ibuprofen can increase the risk of bleeding, especially if taken in high doses or combined with other blood thinners. There is also a potential for muscle problems, such as myopathy or rhabdomyolysis, which are rare but serious side effects associated with statins like Lipitor. People should consult their healthcare provider before using these medications together to assess individual risk factors [1][2].

Sources:
1. DrugPatentWatch.com
2. Relevant medical guidelines.