Medication for excessive urine production in patients treated with tolvapta

Recruitment & Eligibility

Status: Authorised-recruitment may be ongoing or finished

Sex: All

Target Recruitment: 12

Inclusion Criteria

1. Diagnosis of ADPKD, based upon modified Ravine criteria
2. Using tolvaptan 120mg daily
3. Age between 18 and 50 years
4. =45 eGFR (CKD-EPI)
5. Providing informed consent

Are the trial subjects under 18? no
Number of subjects for this age range:
F.1.2 Adults (18-64 years) yes
F.1.2.1 Number of subjects for this age range 12
F.1.3 Elderly (>=65 years) no
F.1.3.1 Number of subjects for this age range

Exclusion Criteria

1. Patients who, in the opinion of the investigator may present a safety risk
2. Patients who are unlikely to adequately comply to the trial’s procedures (due for instance to medical conditions likely to require interruption or discontinuation, history of substance abuse or non-compliance)
3. a. Patients taking medication likely to confound endpoint assessments (e.g. NSAID or diuretics such as furosemide or spironolactone)
3. b. Patients having concomitant illnesses likely to confound endpoint assessments such (e.g. diabetes mellitus for which medication is needed or diabetes insipidus)
4. Women who are pregnant or breastfeeding
5. Patients with known contra indications to the study medication such as
5. a. Hydrochlorothiazide: gout, hepatic impairment, illnesses that cause potassium loss, history of hypokalaemia, known allergy to hydrochlorothiazide
5. b. Metformin: Illnesses that can cause tissue hypoxia (e.g. recent myocardial infarction, heart failure, respiratory failure), known allergy to metformin

Study & Design

Study Type: Interventional clinical trial of medicinal product

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Main Objective: To demonstrate whether hydrochlorothiazide or metformin can diminish aquaresis in patients with ADPKD who are treated with tolvaptan as measured by 24-hour urine volume. ;Secondary Objective: -To assess change in glomerular filtration rate (as measured with the iohexol plasma clearance technique) <br> -To assess change in plasma copeptin <br> -To assess tolerability of the study medication <br>;Primary end point(s): Change in 24-hour urine volume;Timepoint(s) of evaluation of this end point: Baseline, and the end of each 2-week treatment period

Secondary Outcome Measures

Name	Time	Method
Secondary end point(s): -Change in glomerular filtration rate (as measured with the iohexol plasma clearance technique) <br>-Change in plasma copeptin <br>-Tolerability of the study medication <br>;Timepoint(s) of evaluation of this end point: Baseline, and the end of each 2-week treatment period. Adverse events: during entire study period