• The evaluation of long-term safety of tolvaptan in patients with ADPKD with various dosing regimens:
  
• Safety:Adverse events,vital signs,clinical laboratory tests,12- lead electrocardiograms.
  

• Change from baseline for:1. Trough Urine Osmolality at steady state. 2. Renal function by estimated GFR 3. Combined volume of the kidneys. 4. Hypertension Assessment. 5. Renal Pain Assessment. 6. Abdominal Girth Assessment 7.PKD Outcomes Survey.
  

Autosomal Dominant Polycystic Kidney Disease is a genetic disease classified by the formation of fluid-filled cysts in the kidneys. The accumulation of these cysts causes the kidneys to enlarge several times the normal size and leads to the eventual loss of renal function and ultimately results in renal failure in end-stage patients. This is a disease with life-threatening implications to those who have it and their family members who may also be affected. Aside from early antihypertensive control and dietary protein restriction, which are presumed to offer a modest degree of protection, most surviving patients require renal replacement therapy (dialysis and transplant) and suffer from high morbidity and mortality.

A rationale for use of tolvaptan in these genetic disorders has been proven, in principle, through use of a variety of animal models. In these models, tolvaptan is effective in halting or reversing the progression of this renal disease.

The current study is being undertaken in order to evaluate whether tolvaptan, an oral AVP inhibitor, will maintain an adequate safety profile and show a potential clinical benefit by reducing total renal volume in the hopes of making an impact upon disease progression.