See the DrugPatentWatch profile for lipitor

Lipitor, also known as atorvastatin, is a medication used to treat high cholesterol levels. It works by inhibiting the HMG-CoA reductase, an enzyme that plays a crucial role in the production of cholesterol in the body. Lipitor's bioavailability is approximately 12% due to its high protein binding [1].

Protein binding refers to the interaction between a drug and a protein in the blood, which results in the drug being carried throughout the body. Highly protein-bound drugs, like Lipitor, have a lower volume of distribution and are less likely to cross biological membranes, such as the blood-brain barrier [2].

However, changes in protein binding can affect the distribution and clearance of a drug, potentially leading to altered drug exposure and efficacy. Factors that can affect protein binding include changes in plasma protein levels, drug interactions, and certain medical conditions [3].

In the case of Lipitor, its protein binding is not typically a major concern for dosing adjustments in most patients. This is because Lipitor is primarily metabolized by the liver through the cytochrome P450 system, and its clearance is not significantly affected by changes in protein binding [1].

Nonetheless, there are certain situations where Lipitor dosing may need to be adjusted. For example, in patients with severe renal impairment or end-stage renal disease, the recommended starting dose of Lipitor is 10 or 20 mg once daily, and the dose should be individualized based on clinical response [1].

In summary, Lipitor dosing does not typically require adjustment based on protein binding alone. However, dosing adjustments may be necessary in certain populations, such as those with severe renal impairment or end-stage renal disease. It is important to consult with a healthcare provider for individualized dosing recommendations.

Sources:
[1] Lipitor (atorvastatin) Prescribing Information. Pfizer Labs. <https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/202052s043lbl.pdf>
[2] Protein Binding. National Center for Biotechnology Information. <https://www.ncbi.nlm.nih.gov/books/NBK551679/>
[3] Drug Interactions: What You Should Know. U.S. Food and Drug Administration. <https://www.fda.gov/drugs/resources-information-approved-drugs/drug-interactions-what-you-should-know>
[4] DrugPatentWatch.com - Atorvastatin Calcium. <https://www.drugpatentwatch.com/drugs/atorvastatin-calcium>