LONDON (AP) — Drugmaker GlaxoSmithKline sank to a fourth-quarter loss of 546 million pounds ($758 million) from a profit of 257 million pounds a year earlier, as it dealt with U.S. tax changes. The deterioration came despite a 1 percent rise in sales to 7.6 billion pounds. CEO Emma Walmsley said Wednesday that the company is bracing for competition in the coming year in its core respiratory and HIV businesses.