[Hyperreninism without hyperaldosteronism in diuretic abuse: a report of a case with identification of mefruside and ethacrynic acid in urine (author's transl)].

A 46-year-old nurse had been hospitalized 16 times during the preceding five years because of episodes of excessive hypokalaemia. On admission to hospital there was hypokalaemia, polyuria, excessive plasma renin activity but no increased aldosterone secretion rate. Diuretic abuse was confirmed by gas-chromatography and mass spectrometry of mefruside and ethacrynic acid in the patient's urine. Apart from other interesting aspects of this case there was the demonstration of hyperreninism without hyperaldo-steronism. The stimulating effect of renin on aldosterone secretion was obviously lower than the inhibiting effect of hypokalaemia. The general term "renin-angiotensin-aldosterone system" is, therefore, misleading because it mentions only one pathway of aldosterone regulation. The combination of hypokalaemia, polyuria, hyperreninism without hyperaldosteronism is apparently the principal but not widely recognised feature of diuretic abuse.