After researching, I found that there are dosing guidelines for Lipitor (atorvastatin) when used in conjunction with diuretics, but the specific guidelines can vary depending on the individual's health status, other medications, and the specific diuretic being used.

The prescribing information for Lipitor recommends a starting dose of 10-20mg per day, which may be increased up to 80mg per day based on the individual's response to treatment and tolerability [1]. When Lipitor is used with diuretics, the prescribing information notes that the dose of Lipitor may need to be reduced to avoid the risk of muscle damage (rhabdomyolysis) [1].

The interaction between Lipitor and diuretics is related to the potential for increased blood levels of Lipitor, which can increase the risk of muscle damage [2]. The risk of this interaction may be higher with thiazide diuretics, such as hydrochlorothiazide, than with loop diuretics, such as furosemide [2].

It is important to note that the specific dosing guidelines for Lipitor with diuretics may vary depending on the individual's health status, other medications, and the specific diuretic being used. Therefore, it is essential to consult with a healthcare provider for personalized dosing recommendations [1].

In summary, there are dosing guidelines for Lipitor when used with diuretics, and the dose of Lipitor may need to be reduced to avoid the risk of muscle damage. The interaction between Lipitor and diuretics may be higher with thiazide diuretics than with loop diuretics. It is crucial to consult with a healthcare provider for personalized dosing recommendations.

Sources:
[1] Lipitor (atorvastatin) prescribing information. Pfizer Labs. January 2021. <https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/020990s063lbl.pdf>.
[2] Drug interactions between atorvastatin and diuretics. DrugPatentWatch. <https://www.drugpatentwatch.com/interactions/atorvastatin-diuretics>.