[An experimental and clinical pharmacological study of the influence of triamterene on the diuretic and saluretic properties of furosemide xantinol].

The diuretic and saluretic effect of furosemide xantinol administered alone and mixed with different amounts of 2,4,7-triamino-6-phenylpteridine (triamterene) have been investigated in rat and man. The presence of triamterene resulted in a dose dependent inhibition of furosemide xantinol induced diuresis in both species. It was necessary to reduce the amount of triamterene present in the mixture to approximately half that of the one theoretically required according to considerations of the recommended therapeutic doses of the two diuretics before significant inhibition was avoided. Nevertheless, this reduced amount of triamterene proved sufficient to inhibit the distal tubular exchange of Na+ for K+ and H+ and a mixture formulated to give the ratio of 40 mg furosemide xantinol (as base) plus 25 mg triamterene (Salidur) was shown to produce a smooth but efficient loss of water and Na+ in the absence of detectable kaliuresis or reduction in urinary pH, thereby reducing the usual risk of inducing hypokalaemic alkalosis.