Biological effect and plasma concentrations of DDAVP after intranasal and peroral administration to humans

DDAVP was administered intranasally (20 micrograms) and perorally (100 and 200 micrograms) to 6 hydrated volunteers. Urine was collected and blood was sampled at intervals for the following 6 hr. In all experiments DDAVP induced a marked and long lasting antidiuretic response. Radioimmunoassay of DDAVP in blood samples made it possible to calculate bioavailability of DDAVP after the two forms of administration. Following intranasal application 11.3% of the dose appeared in the blood and the figures for oral administration was 0.7-1.0%. Based on analysis of the amount of DDAVP excreted in the urine the urinary clearance rate was estimated to be 0.10 ml/min/kg body wt.