Pharmacodynamics of basic triamterene derivatives.

Triamterene derivatives with a basic side chain and with an additional hydroxyl group in their side chain (hydroxy bases) were investigated for their effects on urine volume and electrolyte excretion in male Wistar rats. All basic derivatives enhance urine volume and sodium excretion. The hydroxy bases show a stronger antikaliuretic effect than the unhydroxylated derivatives. In the group of hydroxy bases the influence of the substitution grade of nitrogen and the role of the pKa values are discussed in order to establish possible structure-activity relationships regarding the antikaliuretic effect.