Background and objective: The study was conducted to compare the standard intravenous route with the intranasal route of desmopressin application and to establish the best time for initiating treatment with desmopressin with the use of the Born test and the PFA 100®-Analyzer for monitoring the therapeutic effect.

Methods: Thirty healthy volunteers (ASA I) with no known bleeding disorder were randomly assigned to an intravenous or an intranasal group in a cross-over design fashion. After obtaining baseline values, the volunteers were given 500 mg aminosalicylic acid for 3 days. On day 4, platelet function tests were performed and desmopressin (0.3 μg kg−1 body weight) was administered either intravenously or intranasally. Born tests (aggregation after stimulation with epinephrine and collagen) were conducted at 30 and 240 min, and PFA 100® bleeding time measurements were conducted at 30, 120 and 240 min after desmopressin administration. Wilcoxon signed rank sum tests or non-parametric ANOVA for repeated measures were used for statistical evaluation.

Results: All volunteers showed a marked decreased platelet function in the Born test (especially if stimulation with epinephrine was used) and an increased PFA 100® bleeding time after treatment with aminosalicylic acid. Platelet function was improved by intravenous as well as intranasal application of desmopressin (P < 0.001) after 30 min. The effect diminished after 4 h in both groups.

Conclusions: Intravenous as well as intranasal desmopressin improved platelet function in healthy volunteers with aminosalicylic acid-induced platelet dysfunction at least 30 min after application. The effect lasts up to 4 h.