Based on the information provided, I cannot confirm whether a specific Lipitor interaction caused a dosage change. However, I can provide some context about Lipitor and its dosage that may help you understand the situation better.

Lipitor, also known as atorvastatin, is a prescription medication used to treat high cholesterol levels and reduce the risk of heart attack and stroke [1]. The dosage of Lipitor typically ranges from 10 to 80 milligrams per day, depending on the patient's needs and medical condition [2].

Drug interactions can occur when Lipitor is taken with certain medications, such as cyclosporine, gemfibrozil, and some antifungal medications [1]. These interactions may increase the risk of muscle damage, kidney damage, or other adverse effects [1]. In some cases, healthcare providers may adjust the Lipitor dosage to minimize the risk of interactions and side effects [1].

To determine whether a specific Lipitor interaction caused a dosage change, it would be necessary to have more information about the patient's medical history, the medication they were taking, and the dosage adjustments made. It is essential to consult with a healthcare provider or pharmacist for personalized advice and recommendations.

In summary, while it is possible that a Lipitor interaction caused a dosage change, I cannot confirm this based on the information provided. Lipitor dosage can vary depending on the patient's needs and medical condition, and healthcare providers may adjust the dosage to minimize the risk of interactions and side effects.

Sources:
[1] Lipitor (atorvastatin) tablets, for oral use [Prescribing Information]. Pfizer Labs; 2016. Available from: <https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/20267s118,20268s108,20269s113,20270s095lbl.pdf>.
[2] Lipitor. DrugPatentWatch.com. Available from: <https://www.drugpatentwatch.com/drugs/lipitor>.