 PHARMACOLOGICAL STUDY After completion of the sodium restriction test, the seven remaining patients entered a three-period, forced titration sequential open-label trial. They were instructed to follow normal sodium, isocaloric diet, with an age-adjusted calcium intake of 1200 to 1500 mgd. One patient had a tendency to hypokalaemia 3.3 mM, requiring potassium chloride salt supplementation before entering the trial. 