UPDATE 1-AstraZeneca smashes forecasts in Q2 after seeing off Pfizer
* Q2 revenue $6.45 billion vs consensus $6.29 billion * Q2 core EPS $1.30 vs consensus $1.10 * Drugmaker raises full-year guidance * Now assuming generic Nexium in U.S. from Oct. 1 (Adds detail on products, background) By Ben Hirschler LONDON, July 31 (Reuters) - A
