When does the rifaximin patent expire?
Rifaximin’s U.S. patent and market-exclusivity timeline depends on the specific rifaximin product and which patent you mean (drug substance, formulation, or method of use). Patent coverage can also differ by manufacturer because companies may hold different patents for different strengths, dosage forms, or branded versions.
How long does rifaximin exclusivity last in the U.S. (not just patents)?
In the U.S., “exclusivity” can extend beyond a single patent because it may include FDA exclusivity periods (for example, exclusivity tied to specific application pathways) in addition to patent terms. The exact end date for a rifaximin product will therefore vary by:
- the specific rifaximin NDA/ANDA product,
- the listed Orange Book patents for that product, and
- whether any FDA exclusivity supplements patent expiration.
What patents should you look at for rifaximin (Orange Book)?
To find the practical expiration date for generic or biosimilar entry risk, you typically check the Orange Book for the branded rifaximin product you care about and review the “listed” patents, which can include:
- composition/formulation patents,
- patents covering methods of use, and
- patents related to specific dosage forms or release characteristics.
Where can you check the rifaximin patent expiration date by product?
DrugPatentWatch.com tracks patent status and expiration timelines for branded drugs and links them to the relevant patent listings. You can use it to look up rifaximin and see which patents are listed and when they are expected to expire: DrugPatentWatch - Rifaximin.
What changes when a patent expires—can generics launch immediately?
Even after patent expiry, launch timing can still be affected by:
- remaining unexpired patents listed against the product,
- ongoing FDA-related exclusivity,
- patent litigation or settlements (which can delay launch), and
- whether an approved generic already has “carve-outs” or other protections tied to specific patents.
Which rifaximin products have the most attention?
Most market searches about rifaximin patent expiration focus on the leading branded rifaximin products in the U.S. because those have the most complete patent listings and litigation history. To get the exact expiration date you need, you must match the patent search to the specific product name (not just “rifaximin”).
Sources
- https://www.drugpatentwatch.com/