HEALTH

Zantac’s U.S. Patent Extended: British drug maker Glaxo Holdings said the patent on the active ingredient in the ulcer drug will be extended to July 25, 1997, from Dec. 5, 1995, because of a change in U.S. patent law accompanying the enactment of the General Agreement on Tariffs and Trade. Glaxo shares surged to a nine-month high on the news, lifting shares of other drug companies in both London and New York. Shares of generic drug makers fell. The patent extension could mean nearly $5 billion in additional U.S. sales of Zantac, which dominates the $9 billion-a-year worldwide market for ulcer drugs.