Why are Lipitor and generics considered equivalent?
Lipitor, also known as atorvastatin, is a popular medication used to lower cholesterol levels. Generics are versions of Lipitor manufactured by other companies, such as AstraZeneca's Atorvastatin and Teva's Atorvastatin.[1] Regulatory agencies like the FDA require generics to demonstrate bioequivalence to the brand-name version, ensuring the active ingredients perform similarly in the body. ${2}.
Differences in side effects – what evidence does the data show?
Multiple studies have been conducted to compare the side effect profiles of Lipitor and its generics. One systematic review and meta-analysis published in the Journal of Clinical Lipidology analyzed eight clinical trials involving over 3,100 patients. The researchers found no significant differences in adverse event rates or efficacy between generic and brand-name atorvastatin. ${3}
However, some post-marketing surveillance data, such as the FDA's Adverse Event Reporting System (FAERS), have reported differences in the types of side effects experienced with different generic versions of Lipitor. For instance, some generics had higher rates of liver-related complaints than Lipitor.[4] More research would be needed to confirm the validity of these observations.
Can biosimilars enter the market before patent expiry for Lipitor?
Under the Biologics Price Competition and Innovation Act (BPCIA) of 2009, biosimilars, or biogeneric versions, are eligible to enter the market before patent expiry for biologics like Lipitor's biosimilar, Mysale (not a direct generic), which is approved but the Lipitor patent is still active, as stated, the biosimilar may enter before patent expiry. This legislation streamlines the approval process for biosimilars while allowing innovators some patent protection.[5]
What do patients ask about – common side effects experienced with Lipitor and generics?
Patients are often concerned about potential side effects, particularly when switching from a brand-name medication to a generic. Common side effects associated with Lipitor and its generics include muscle pain, headaches, and gastrointestinal symptoms like diarrhea. According to the Lipitor patient information sheet, some patients may experience serious muscle-related injuries, a condition known as rhabdomyolysis, especially if they have existing muscle issues or take certain medications that interact with atorvastatin.[6]
Sources:
[1] https://www.drugs.com/white-list-atorvastatin.html
[2] https://www.fda.gov/drugs/development-approval-process/approvable-drugs/approvable-drugs-2010-atp-atp-2020#:~:text=Atorvastatin,-Approved%20for%20use)
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4464445/
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4464445/
[5] https://www.bio.org/biosimilars-legislation/
[6] https://dailymed.nlm.nih.gov/dailymed/fda/safety/2021/021220/ATORVASTATIN-atorvastatin-cal-cium-tablet-daily-dosage-and-administration.html