PRESS RELEASE: Adams Respiratory Therapeutics Receives Notice of Paragraph IV Certification

Adams Respiratory Therapeutics Receives Notice of Paragraph IV Certification Against Patents for Guaifenesin 600 mg Single-Ingredient Extended-Release Tablets

CHESTER, N.J., August 21, 2007 — Adams Respiratory Therapeutics, Inc. today announced that it has received a Paragraph IV Certification Notice letter, advising that Perrigo R&D Co., has submitted an Abbreviated New Drug Application (ANDA) for guaifenesin 600 mg single-ingredient extended-release tablets.

Adams currently markets Mucinex SE, single-ingredient 600 mg extended-release guaifenesin, the only available FDA-approved extended-release, single-ingredient guaifenesin product. In addition, Adams' portfolio of patent-protected, extended-release guaifenesin products includes Mucinex DM and Mucinex D; and the Company recently launched a new line of 1200 mg maximum strength extended-release guaifenesin products under the Mucinex name. None of these other products are the subject of this certification letter. Adams has two patents that protect its suite of extended-release guaifenesin products and these patents are listed in the Food and Drug Administration (FDA) Orange Book and expire in 2020.

Perrigo's certification letter sets forth allegations that Adams' U.S. Patents 6,372,252 and 6,955,821 are invalid and/or will not be infringed by Perrigo's manufacture, use or sale of the product for which the ANDA is submitted, and reserves the right to raise unenforceability defenses.

Adams plans to vigorously defend its market position for single-entity Mucinex as well as its patent portfolio protecting the Company's oral solid, extended-release guaifenesin products. Adams is evaluating Perrigo's notice letter and has 45 days to commence a patent infringement lawsuit against Perrigo that would automatically stay the FDA from approving Perrigo's ANDA for 30 months or until a district court decision that is adverse to Adams, whichever may occur earlier.

About Adams Respiratory Therapeutics, Inc.

Adams is a specialty pharmaceutical company focused on the late-stage development, commercialization and marketing of over-the-counter and prescription pharmaceuticals for the treatment of respiratory disorders.