From the Guidelines
For patients with polycystic kidney disease, tolvaptan is the recommended treatment to delay disease progression, as it has been shown to slow the decline in eGFR and reduce the growth of total kidney volume. The use of tolvaptan, an antagonist of the vasopressin-2 receptor, has been found to have a net difference in eGFR decline of 1.3 ml/min per 1.73 m2 per year and in total kidney volume growth of 2.7% 1. This treatment should be initiated with a daily dose of 45 mg upon waking, and of 15 mg 8 hours later, and titrated gradually by the treating physician to permit adequate tolerability 1. It is essential for patients to have a "sick-day plan" and be advised to skip doses of tolvaptan in situations in which they are at risk of volume depletion 1.
Key considerations for tolvaptan treatment include:
- The need to drink enough water to replace urinary losses and ensure long-term tolerability 1
- The importance of individual adjustments to the schedule, timing, and doses of tolvaptan based on the person's activities 1
- Counseling patients to drink liquids without sugar or fat and to adopt a low-sodium intake to reduce polyuria 1
- Monitoring for potential side effects, such as UTI, kidney stones, hematuria, and kidney pain events, which were significantly reduced in the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Its Outcomes (TEMPO) 3:4 trial 1.
Overall, the use of tolvaptan has been shown to be effective in delaying the progression of ADPKD, and its benefits outweigh the potential risks 1.
From the Research
GNR2 for Polycystic Kidney Disease
- There is no direct mention of GNR2 in the provided studies, however, the studies discuss the role of the renin-angiotensin-aldosterone system (RAAS) in the pathogenesis of hypertension in patients with autosomal dominant polycystic kidney disease (ADPKD) 2, 3, 4, 5, 6.
- The studies suggest that inhibition of the RAAS using angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin II receptor blockers (ARB) may be beneficial in managing hypertension in ADPKD patients 2, 3, 4, 5, 6.
- One study found that intensive control of systolic blood pressure to 95-110 mmHg was associated with a 14% slower rate of kidney volume growth compared to standard control, but it is unclear whether this result was due to greater blockade of the RAAS or due to the lower blood pressure per se 5.
- Another study found that ACE-I dominated ARB and displayed greater cost-effectiveness due to lower cost and increased capacity to prolong years of life without transplant or death among hypertensive ADPKD patients 6.
- The studies highlight the importance of managing hypertension in ADPKD patients to slow disease progression and reduce the risk of cardiovascular disease and end-stage renal disease 2, 3, 4, 5, 6.