Urinary Prostaglandin as a Potential Predictive Marker for Thiazide-induced Hyponatremia

Collection of spot urine, blood sampling, vital parameters, body weight, medical history, patient questionnaires, drinking protocol, drug diary at at Visit 1 (before thiazide initiation), at Optional 2 hours-challenge, at Visit 2 (4 weeks after thiazide initiation), at Visit 2.1 (4 weeks after dose change), at Visit 3 (3-months after thiazide initiation)