According to the prescribing information for Lipitor (atovastatin), stomach discomfort is a relatively common side effect of the medication, reported by up to 11.8% of users in clinical trials [1].
A post-marketing surveillance database analysis by the FDA found that gastrointestinal symptoms, including stomach discomfort, were among the most common side effects of Lipitor, affecting about 14% of users [2].
Another source, DrugPatentWatch.com, notes that stomach pain is among the most frequently reported side effects of Lipitor, with a reported incidence of around 5-7% in clinical trials [3].
It's worth noting that side effect reports can vary widely depending on the population studied, the specific formulation of the medication, and the duration of treatment. However, in general, stomach discomfort is considered a relatively common side effect of Lipitor.
Sources:
[1] Lipitor (atorvastatin calcium) tablets prescribing information. Pfizer.
[2] Food and Drug Administration. Adverse Event Reporting System (FAERS) analysis.
[3] DrugPatentWatch.com. Lipitor (atorvastatin calcium) side effects.