In April 2010, the ZYRTEC brand manager at Johnson & Johnson's McNeil Consumer Healthcare, learned that Sanofi's Allegra, the leading brand in the prescription antihistamine category, was anticipated to secure over-the-counter (OTC) approval by spring 2011. With the recent successful launch of ZYRTEC Liqui-Gels, ZYRTEC was poised to overtake Merck's Claritin, the leader in the OTC antihistamine category. The case asks students to recommend how a strong brand might respond to a new market entrant that threatens to disrupt the category. The case is used in Darden's Consumer Brands elective course and would fit in courses covering consumer marketing, brand marketing, or brand strategy as well as a first-year marketing management course. Although written for an MBA audience, the content and decision points are easily accessible to advanced undergraduate marketing students and an Executive Education audience.