Pharmacokinetics and Pharmacodynamics of Desmopressin Oral Lyophilisate Formulation in the Paediatric Population

Pharmacokinetics and Pharmacodynamics of Desmopressin Oral Lyophilisate Formulation in the Paediatric Population

Patients suffering from nocturnal enuresis (starting from the age of 5 till adulthood) are all treated with the same dose of desmopressin, i.e. 120mcg once daily. In treatment resistant enuresis, this dose is doubled: those patients take 240mcg once daily. A pilot study performed at our department showed a correlation between weight and plasma concentration when a fixed dose of desmopressin oral lyophilisate formulation was given to the pediatric patient (older than 6 years). This study will investigate the pharmacokinetics (PK) and pharmacodynamics (PD) of desmopressin in young children, less than 8 years old. Additionally, the efficacy of desmopressin oral lyophilisate formulation in urinary concentration testing will be evaluated

Inclusion Criteria:

• Children with an uro- and/or nephropathy who need an urinary concentration test OR Children with monosymptomatic nocturnal enuresis (based on nocturnal polyuria) with treatment failure on desmopressin tablet
• Otherwise healthy children (on medical history and physical examination)
• Parents or legal guardian of the child signed the informed consent form
• Age: between 6 months and 8 years
• Minimum weight: 8 kg

Exclusion Criteria:

• Diabetes insipidus
• Renal failure (eGFR<60ml/min/1,73m²)
• Current urinary tract infection
• Syndrome of inappropriate antidiuretic hormone secretion
• Heart failure
• Clinical significant medical conditions (renal, hepatic, gastro-intestinal, pulmonary, cardiac, endocrinologic) that might interfere with the clinical endpoints
• Sensitivity to desmopressin or excipients of the oral lyophilisate formulation
• Use of antibiotics, diuretics or other drugs that can influence diuresis (tricyclic antidepressants, chlorpropamide, oxcarbazepine, selective serotonin reuptake inhibitors, chlorpromazine and carbamazepine).
• Use of drugs that influence intestinal motility (such as loperamide)
• Anomalies of the mouth that might interfere with the intake / absorption of the medication