Desmopressin Melt Therapy in Patients With Nocturnal Polyuria: a Pharmacokinetic/Dynamic Study

The objective of this study is to find out what the pharmacokinetic/dynamic (PK/PD) characteristics of desmopressin melt are in nocturia patients (compared to healthy volunteers and children). The main questions the investigators want to answer are: Are differences related to the pathophysiological factors involved in nocturia? Are there age/gender/size differences? Can the investigators identify patients who are likely to develop hyponatraemia? Can the investigators individualize treatment and reduce risk for hyponatraemia? Day 1: Patient is being hospitalized in the morning General anamnesis and clinical examination Uroflow and residue measurements (3x) Sober blood sample, to determine plasma concentrations of Na+, Cl-, osmolality and creatinin Day 1-2: - In the evening at 20h: start (with empty bladder!) 24h miction-incontinence-residue registration: urine collections every 3 hours (every portion of urine within a period of 3 hours must be collected in the same collection device), with: registration of volumes and measurement urinary concentrations of Na+, Cl-, osmolality and creatinin Measurement of blood pressure during 24h Day 2-3: In the evening at 19h (day 2): drink 15mL/kg water At 20h: take desmopressin melt 120µg + start: 24h miction-incontinence-residue registration: registration of volumes and measurement urinary concentrations of Na+, Cl-, osmolality and creatinin (U1-U7) Measurement of blood pressure during 24h Collection of urine:U1 at 19h, U2 at 20h, together with intake of first desmopressin melt, U3 at 21h = 1h after desmopressin melt intake, U4 at 22h = 2 after desmopressin melt intake,U5 at 23h = 3h after desmopressin melt intake, U6 at 2h (day 3) = 6h after desmopressin melt intake, U7 at 8h = 12h after desmopressin melt intake Blood samples for blood levels of desmopressin: 1h, 2h, 3h, 6h after desmopressin melt intake, 12h after desmopressin melt intake + plasma concentrations of Na+, Cl-, osmolality and creatinin (safety profile) At 8h in the morning (day 3): drink 15mL/kg water + collection of urine per hour during 3h with measurement of urinary concentrations of Na+, Cl-, osmolality and creatinin: U8 at 9h, U9 at 10h, U10 at 11h Patient can go home on day 3, unless he is at high risk for side effects, high-risk patients are hospitalized for 7 days

Pharmacokinetic and dynamic evaluation of desmopressin melt for treatment of nocturnal polyuria in adults

blood analysis for plasma concentration of desmopressin: 1h, 2h, 3h, 6h and 12h after drug intake urine analysis for urinary concentration of sodium, potassium, creatinin and osmolality: after water load with 15ml/kg body weight (evening day 2): the moment of drug intake, 1h, 2h, 3h, 6h and 12h after drug intake after water load with 15ml/kg body weight (morning day 3): 1h, 2h, 3h after water load

24h miction-incontinence-residu registration: urine collections every 3 hours (every portion of urine within a period of 3 hours must be collected in the same collection device), with: Registration of volumes Measurement urinary concentrations of Na+, Cl-, osmolality and creatinin

Inclusion Criteria: written informed consent prior to the performance of any study-related activity patients, men and woman, 18 years and older, with nocturnal polyuria, resulting in nocturia (2 voids or more at night) and/or nocturnal incontinence. Exclusion Criteria: hypersensitivity/anaphylactic reaction on desmopressin or one of the other substances pregnancy genitourinary tract pathology (infection, tumor,...) urolithiasis suspicion or evidence of cardiac failure moderate to severe renal insufficiency (creatinin clearance < 50 ml/min) psychogenic or habitual polydipsia hyponatraemia or predisposition for hyponatraemia diabetes insipidus syndrome of inadequate ADH production