BUZZ-AstraZeneca: FDA approves co's potassium control drug
** Shares (Berlin: DI6.BE - news) of AstraZeneca (NYSE: AZN - news) up 2 pct after co's potassium control drug approved in the US
** Stock top pct gainer on the FTSE 100
** Co's Lokelma approved in the US for the treatment of adults with hyperkalaemia, a serious condition characterised by elevated potassium levels in the blood
** Shares of AZN have risen 4.5 pct this year