See the DrugPatentWatch profile for lipitor

Lipitor, also known as atorvastatin, is a medication used to treat high cholesterol levels. It works by inhibiting HMG-CoA reductase, an enzyme that plays a crucial role in the production of cholesterol in the body [1]. Protein binding refers to the interaction between a drug and proteins in the bloodstream, which can affect the drug's distribution, metabolism, and excretion [2].

In the case of Lipitor, it is highly protein-bound, with approximately 98% of the drug bound to plasma proteins [3]. Protein binding can impact kidney filtration in several ways. Firstly, only the unbound fraction of a drug is available for filtration by the kidneys [4]. Therefore, since Lipitor is highly protein-bound, only a small fraction of the drug is freely available for filtration by the kidneys.

Additionally, protein binding can affect the rate of drug clearance by the kidneys. Protein-bound drugs are typically cleared more slowly than unbound drugs, as the bound fraction is not readily filtered by the kidneys [5]. However, it is important to note that Lipitor is primarily metabolized by the liver, with only a small fraction (less than 2%) of the drug excreted unchanged in the urine [3].

Overall, while Lipitor's high protein binding can impact its distribution and clearance, it has limited implications for kidney filtration, as the drug is primarily metabolized by the liver.

Sources:

1. "Atorvastatin." National Library of Medicine, <https://medlineplus.gov/druginfo/meds/a601262.html>.
2. "Protein Binding." National Center for Biotechnology Information, <https://www.ncbi.nlm.nih.gov/books/NBK551680/>.
3. "Atorvastatin Calcium Tablets, for Oral Use." DailyMed, <https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=832e8e1e-9e5d-4e1f-a8f8-6f8a5e8f8d68&type=display>.
4. "Renal Drug Clearance." National Center for Biotechnology Information, <https://www.ncbi.nlm.nih.gov/books/NBK551679/>.
5. "Protein Binding and Drug Clearance." National Center for Biotechnology Information, <https://www.ncbi.nlm.nih.gov/books/NBK551681/>.