Lipitor is a medication that is used to lower cholesterol levels in the blood. According to Drug Patent Watch [1], the active ingredient in Lipitor is atorvastatin calcium. However, the sources provided do not mention any direct link between Lipitor and stomach upset caused by skim milk.

While skim milk is often recommended as a remedy for heartburn, it is not clear whether it would be helpful or harmful when taken with Lipitor. According to BuzzRX [2], milk can help neutralize stomach acid and alleviate heartburn symptoms. However, it is also important to note that dairy products can trigger inflammation in some people, especially those with arthritis [3].

In conclusion, while there is no evidence to suggest that Lipitor can cause stomach upset when taken with skim milk, it is important to be aware of the potential side effects of both Lipitor and dairy products. It is recommended that patients consult with their healthcare provider to discuss any concerns or questions about taking Lipitor with skim milk or other dairy products.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.buzzrx.com/blog/does-milk-help-heartburn-other-remedies-and-cures
[3] https://www.arthritis.org/health-wellness/healthy-living/nutrition/healthy-eating/dairy-and-inflammation