UPDATE: Fitch Affirms Ratings on Merck; Outlook Lowered from Positive to Negative

Fitch Ratings has affirmed Merck & Co.'s (NYSE: MRK ) ratings, including the Issuer Default Rating (IDR) at 'A+'. The Rating Outlook is revised to Negative from Positive. A full list of ratings affirmed is listed below. The ratings apply to approximately $20.5 billion in outstanding debt. KEY RATING DRIVERS Leveraging Share-Buybacks Pressure Credit Profile On