The asthma drug Zyflo (zileuton) is available only as a brand-name drug. It is unclear why no generic versions are available, as the patent for Zyflo expired in 2010. Zileuton is the active ingredient in Zyflo. Some people refer to it as the generic name; however, this is not the same as a generic version of Zyflo.
In February 2008, the manufacturer of Zyflo announced that it has discontinued making this product. The manufacturer stated that since the longer-acting version, Zyflo CR, became available in 2007, use of immediate-release Zyflo declined significantly. Zyflo CR will still be available.
An Overview of Zyflo Generic
Zyflo® (zileuton) is a prescription medication used to prevent asthma attacks. It is part of a group of medications called leukotriene synthesis inhibitors.
Zyflo is manufactured by Critical Therapeutics, Inc. At this time, there are no generic versions approved for sale in the United States.
When Will Generic Zyflo Be Available?
The patent for Zyflo expired in December 2010. However, no generic versions are available, for reasons that are unclear. Perhaps it is not financially beneficial for a generic manufacturer to apply to make a generic version of Zyflo, since the drug has a relatively small market. It is difficult, if not impossible, to accurately predict when exactly a generic version may become available.
Is Zileuton a Generic Zyflo?
The answer is no. Zileuton is the active ingredient in Zyflo but is not a generic version of the drug. What can be confusing is that, oftentimes, the active ingredient of any drug is referred to as its "generic name." The generic name of a medicine is different from a generic version of it. In order for there to be a generic version of a medicine, the original medicine must have gone off patent and another company besides the original manufacturer must have made the product.
Written by/reviewed by: Kristi Monson, PharmD;Arthur Schoenstadt, MD
Food and Drug Administration, Center for Drug Evaluation and Research. Electronic orange book: approved drug products with therapeutic equivalence evaluations. FDA Web site. Available at: http://www.fda.gov/cder/ob/. Accessed June 10, 2011.
eMedTV serves only as an informational resource. This site does not dispense medical advice or advice of any kind.
Site users seeking medical advice about their specific situation should consult with their own physician. Click