Comparison of the antidiuretic effects of single intravenous and intranasal doses of DDAVP in diabetes insipidus.

In 13 patients with hypothalamic diabetes insipidus after daily single intravenous (0.04–24 µg) and single intranasal (5–320 µg) doses of 1-deamino-8-D-arginine vasopressin (DDAVP) the relationships between the log doses and antidiuretic responses (log osmolalities of 24-hour urine samples) were compared. On the basis of such comparisons the ratio of nasal per venous daily single dose requirement was determined and found to be 26:1. Similarly, the relative potency of venous DDAVP was investigated in two subgroups of patients classified according to their response to peroral drugs. Seven times more DDAVP was required for patients treated previously with high doses of peroral antidiuretics. It was concluded that in groups of patients with divergent peroral dose requirements different DDAVP single-dose treatment schedules should be planned.