Enhancing the efficacy of lithium treatment by combined use with diuretics and low sodium diets: a preliminary report.

Because reports have indicated that sodium metabolism may bear some influence on manic-depressive illness, the present study was designed to test the efficacy of sodium depletion in enhancing lithium's therapeutic effect. Twenty-seven manic patients refractory to lithium doses producing therapeutic serum lithium levels were subjected to lithium alone, lithium in combination with a thiazide diuretic, and lithium in combination with a low sodium diet. Results indicated that such combinations could be helpful in reducing manic symptoms in the majority of patients without engendering undue toxicity. While mechanisms of action remain to be elucidated, it appears that such combinations may be safely administered to those manic patients not responding to lithium alone or to those requiring lithium but suffering either a lithium-induced nephrogenic diabetes insipidus or other severe side effects. However, caution is still advised in employing these combinations until further, better controlled research substantiates these preliminary data.