Effects of hydrochlorothiazide plus sotalol on acute urinary electrolyte excretion in normal subjects

Twenty-four-hour urinary outputs, total volume and urinary chlorine (Cl), sodium (Na), potassium (K), calcium, magnesium (Mg), total inorganic phosphate and creatinine levels were measured in 12 biologically equivalent healthy volunteers given single oral doses of placebo, hydrochlorothiazide (HCTZ) 50 mg and a combination of HCTZ and sotalol (STL) 320 mg in a double-blind, random study. HCTZ and HCTZ + STL increased urinary volume and Na, K, Cl, phosphate and Mg levels significantly and to a similar extent. Since HCTZ causes hyperkaliuresis and hypermagnesiuresis with or without simultaneous administration of STL, the latter does not change the acute effects of HCTZ in healthy subjects.