There is only one effective treatment for polycystic kidney disease (PKD): the vasopressin V2 receptor antagonist (V2RA) tolvaptan. If started early, V2RA-treatment can postpone kidney failure by 5-10 years. As a side-effect V2RA-treatment causes increased urine production of 6-8 L per day, which impacts tolerability and limits implementation in clinical care. In a pilot RCT by our group, hydrochlorothiazide (HCT) decreased urine production by 25%, improved quality of life and showed indications of potentiating the V2RA renoprotective effect. If proven true, this would imply that adding HCT to a V2RA would lead to health benefit in a very cost-effective way.
Addition of HCT will improve the renoprotective effect of V2RAs in PKD patients, while simultaneously mitigating side-effects and improving quality of life.
Double-blind, randomized placebo-controlled 3-year trial testing superiority.
Adult PKD-patients on stable dose of V2RA-treatment without contra-indications to HCT
Oral Hydrochlorothiazide 25 mg once daily
Rate of kidney function decline as calculated with linear mixed models, quality of life, V2RA dose used, V2RA discontinuation rate, 24-hour urine volume and safety.
Estimated sample size is 300 patients. Data analysis will be performed by an independent statistician who will assess differences in outcome measures between HCT and placebo, in an intention to treat analysis.