[Pharmacological and toxicological properties of the saluretic xipamide (4-chloro-5-sulfamoyl-2',6'-salicyloxylidide)].

Xipamide (4-chloro-5-sulfamoyl-2',6'-salicyloxylidide, Aquaphor), a new compound is a derivate of salicylic acid with marked sodium and water excreting potency. Its effect is dosage dependent. Dosages as low as 0.001 mg/kg p.o. in rats and 0.04 mg/kg p.o. in dogs lead to a statistically significant increase of sodium and water excretion. Potassium excretion was less affected and showed to be rather constant in a dosage range between 0.01 and 10.0 mg/kg. In rats a maximum of sodium and water excretion could be reached by a dose of 200 mg/kg duration of action in rats was approximately 10 h. In dogs a statistically significant sodium and chloride excretion could be detected after oral application of 0.04 mg/kg. Xipamide increased diuresis started with an oral dose of 0.1 mg/kg. Intravenous application of xipamide in a dose of 0.2 mg/kg in dogs accompanied by permanent infusion of 5 per cent mannit solution clearly showed the diuretic profile of the substance: increased diuresis started within 40 min. A peak was reached within 40-60 min post injectionem. Then excretion decreased slowly. Even 120 min post injectionem a diuretic action could be detected. Diuresis and sodium excretion could be demonstrated in rats with experimentally predamaged kidneys and with steroid dependent sodium retention. As could be demonstrated in hypertensive rats xipamide had a hypotensive effect, normotensive rats were not affected. In animal studies xipamide was excellently tolerated. The therapeutic range of the substance was high in single doses as well as when the drug administered over 6 weeks.