
nephrogenic diabetes insipidus
chlorothiazide has been found of value in
establishing and maintaining adequate hydra-
tion in some patients; its exact mechanism of
action is not known.  the antidiuretic effects
of chlorothiazide and its analogues have been
studied in six patients with ndi, two of
whom were infants less than six months of
age.  dehydrated infants showed a dramatic
response to treatment.  with those unable to
achieve an optimal fluid intake prior to treat-
ment, the initial beneficial response was asso-
ciated with an increased fluid intake.  follow-
ing this initial antidiuretic response, a vari-
able degree of "escape" or resistance to the
action of the drug commonly occurred.  de-
spite the unpredictability of a prolonged anti-
diuretic response, a therapeutic trial of chloro-
thiazide in ndi seems warranted if diet alone
is not sufficient to maintain hydration.  it must
be remembered, however, that this drug is po-
tentially toxic.
