In 1999, the Randomized Aldactone Evaluation Study (RALES) demonstrated that spironolactone reduced mortality from 46% to 35% in patients with a history of severe heart failure.1 A subsequent review in the American Family Physician journal concluded that spironolactone is safe, easy to use and reasonably priced.2 In February 2016, the MHRA advised that “concomitant use of spironolactone with ACEi or ARB is not routinely recommended because of the risks of severe hyperkalaemia, particularly in patients with marked renal impairment”.3 One of the triggers for the warning came from a coroner's Regulation 28 report on a patient who had died from hyperkalaemia associated with the use of spironolactone and lisinopril. Nevertheless, the MHRA advice seemed out of step with …