[Lithium-induced chronic water-metabolism disorder (nephrogenic diabetes insipidus)]

Lithium may induce all clinical physiological abnormalities of the polydipsia- polyuria syndrome. Authors describe a 61-year-old woman patient in whom permanent disturbance of the water metabolism, nephrogenic diabetes insipidus (NDI) was caused by lithium treatment, lasting longer than 10 years. The partial resistance of the fluid disturbance to vasopressin has been investigated by the administration of supramaximal doses of dDAVP. Considering the known antidiuretic effect of indomethacin, authors compared antidiuruetic activity of indomethacin and piroxicam (Hotemin) by studying standard parameters of water metabolism/free water clearance ect.) It was found that piroxicam, on mg basis a more effective antiinflammatory compound, was less antidiuretic then indomethacin. It was concluded, that there is no close parallelism between the structure and antiinflammatory and antidiuretic activity of nonsteroid antiinflammatory drugs. In the opinion of authors nonsteroid antiinflammatory drugs may have a role in the treatment of lithium-induced NDI, though, the establishment of the safety use of such therapy requires further studies.