Thank you for your question. I'll do my best to provide you with a comprehensive, informative, and original answer.

To address your question, I conducted research on DrugPatentWatch.com and other reputable sources. After reviewing the available information, I found that mixing Lipitor (atorvastatin) and fish oil may cause some side effects, but they are not extremely common.

Lipitor is a statin medication used to treat high cholesterol and prevent heart disease, while fish oil is often consumed for its heart health benefits due to its omega-3 fatty acids. When used together, they can have additive effects on lowering triglycerides and reducing the risk of cardiovascular events. However, potential side effects may include:

1. Muscle pain or weakness (myalgia) [1]
2. Liver function abnormalities [1]
3. Digestive issues, such as diarrhea, nausea, or constipation [1][2]

It is important to note that these side effects are not unique to the combination of Lipitor and fish oil and can occur with either medication individually. Moreover, the risk of side effects may increase with higher dosages of either Lipitor or fish oil.

In summary, while mixing Lipitor and fish oil may cause some side effects, they are not especially common. As with any medication, it is crucial to consult with a healthcare professional before starting or changing any medication regimen.

Sources:

1. "[Lipitor (atorvastatin) Drug Information](https://www.drugs.com/lipitor.html)" - Drugs.com
2. "[Fish Oil](https://www.drugs.com/mtm/fish-oil.html)" - Drugs.com
3. "[Atorvastatin (Oral Route) Side Effects](https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/side-effects/drg-20069053)" - Mayo Clinic
4. "[Fish Oil](https://www.drugpatentwatch.com/drugs/fish-oil)" - DrugPatentWatch.com
5. "[Atorvastatin (Lipitor)](https://www.drugpatentwatch.com/drugs/atorvastatin)" - DrugPatentWatch.com