Based on the available information, there are a few drugs and substances that can interact harmfully with Lipitor (atorvastatin), particularly in relation to the liver.

Firstly, according to the Mayo Clinic, grapefruit and grapefruit juice can interact with Lipitor and other statins, potentially leading to liver damage [${2}]. This is because grapefruit can inhibit the enzyme that breaks down the statin, leading to increased levels of the drug in the body.

Secondly, the National Center for Biotechnology Information (NCBI) states that certain medications, such as cyclosporine, fibric acid derivatives, niacin, and erythromycin, can increase the risk of liver damage when taken with Lipitor [${3}]. This is because these drugs can also affect the metabolism of Lipitor, leading to increased levels of the drug in the body and potentially damaging the liver.

It is important to note that while these interactions can occur, they do not necessarily mean that they will occur in every individual. However, it is always best to consult with a healthcare provider before starting or stopping any medication, especially if there are concerns about potential drug interactions.

Sources:
[1] <https://www.drugpatentwatch.com/p/tradename/LIPITOR>
[2] <https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013>
[3] <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3589309/>