Conditions: Autosomal Dominant Polycystic Kidney Disease
Allocation: NON_RANDOMIZED | Intervention model: PARALLEL
Enrollment: 29
Healthy volunteers: no

Brief summary:
The purpose of the trial was to determine the short-term effects of tolvaptan in patients with autosomal dominant polycystic kidney disease (ADPKD) at various levels of renal function.

Detailed description:
Renal function was assessed during screening with the estimated glomerular filtration rate (eGFR), which was calculated with the 4-variable modification of diet in renal disease (MDRD) equation using a minimum of 2 creatinine measurements. The eGFR values were used to categorize participants into 1 of 3 mutually exclusive strata (\> 60 \[Group A\], 30 to 60 \[Group B\], and \< 30 \[Group C\] mL/min/1.73 m\^2). Each of the 3 groups received the same tolvaptan treatment.

During the 3-week treatment period, participants were up-titrated on a weekly basis from 45/15 mg to 60/30 mg to 90/30 mg (AM and PM \[8 hours later\] split-dose) to the maximally tolerated dose. The 3-week treatment period was followed by a 3-week post-treatment period during which no study medication was administered.

The effects of the highest tolerated split-dose of tolvaptan on renal hemodynamics and pharmacokinetic and pharmacodynamic parameters were assessed throughout the 6 weeks of the study. The reversibility of changes during the post-treatment period after withdrawal of the drug was determined and the acute transitory effects on kidney volume were also explored.

Arms:
arm 1: Participants received tolvaptan for the first 3 weeks of the 6 week study. Participants were up-titrated on a weekly basis from tolvaptan 45/15 mg to 60/30 mg to 90/30 mg oral split-dose (AM and PM \[8 hours later\]) to the maximally tolerated dose. arm 2: Participants received tolvaptan for the first 3 weeks of the 6 week study. Participants were up-titrated on a weekly basis from tolvaptan 45/15 mg to 60/30 mg to 90/30 mg oral split-dose (AM and PM \[8 hours later\]) to the maximally tolerated dose. arm 3: Participants received tolvaptan for the first 3 weeks of the 6 week study. Participants were up-titrated on a weekly basis from tolvaptan 45/15 mg to 60/30 mg to 90/30 mg oral split-dose (AM and PM \[8 hours later\]) to the maximally tolerated dose.

Interventions: intervention 1: Tolvaptan
Intervention descriptions: intervention 1: Tolvaptan was supplied as 15 and 30 mg tablets.

Protocol document: