In a randomized cross-over study the saluretic effect of furosemide-retard was compared with the combination of furosemide-retard/triamterene in 10 healthy male volunteers. The combination led to a significantly stronger excretion of sodium and a significantly lower excretion of potassium than furosemide-retard. The interaction of the saluretic with the antikaliuretic was even more distinctly expressed regarding sodium related quotients. The combination furosemide-retard/triamterene differs significantly from furosemide-retard in the main considering Na+/Cl-, Na+/K+ and Na+/Mg2+ quotients. The concentration time curves for furosemide and OH-TA-sulphate in the plasma are nearly similar. Maximal plasma levels for furosemide are reached after 3.9h and for OH-TA-sulphate after 2.2h. The 'apparent' elimination half-life time for furosemide is 2.1h and the elimination half-life time for OH-TA-sulphate is 2.0h.