Management of Polycystic Kidney Disease
Renal function usually remains normal until a polycystic kidney disease (PKD) patient reaches his or her forties. After that, the glomerular filtration rate (GFR–measurement of kidney function) declines steadily and irreversibly.
Since there are co-morbidities associated with (or caused by) PKD, treatment of them is part of a combined approach to global care.
Elevations in blood pressure are common in PKD patients, often before any decrease in kidney function. Due to the kidney’s role in blood pressure maintenance (the renin-angiotensin system), an angio-converting enzyme (ACE) inhibitor is used as an initial antihypertensive medication. When kidney failure progresses enough to cause a rise in serum creatinine, a beta blocker can be used to keep the blood pressure in normal range (for PKD patients, <130/80).
Low Sodium Diet
As PKD progresses, more sodium is excreted. This can be counteracted by decreasing sodium intake (dietary alteration–low sodium diet). Sodium restriction can slow the progress of PKD.
Statins for Dyslipidemia
Abnormal cholesterol and triglyceride levels should be treated aggressively with statin drugs, since chronic kidney disease is a major risk factor for coronary heart disease.
Vasopressin, also called “Anti-diuretic Hormone” (ADH), is a hypothalamic-made, pituitary-released hormone that controls water conservation in the kidney. Tolvaptan is a drug that suppresses vasopressin, and this action has been shown to slow down the growth of cysts and decrease the rate of GFR decline. Because it can cause liver toxicity and other side effects, however, it is primarily used in those who are high-risk for rapid PKD progression as determined by serial ultrasonography and GFR testing.
Increased Fluid Intake
Increasing fluids will suppress the natural vasopressin levels, which is a safer way than using tolvaptan, and therefore no risk to all patients with PKD. Increased fluids also dilutes minerals, decreasing the risk of stone formation.
Natural somatostain inhibits the release of insulin, glucagon, and other pancreatic products. Octreotide, a somatostatin analog (mimics somatostatin), has been shown to decrease the accumulation of fluid in PKD cysts and slow the enlargement of the kidneys and liver that is part of the disease. It also slows GFR decline.
Treatment for ESRF
Eventually, end-stage renal failure requires another method to clear toxic wastes from the body other than the failed kidneys. This consists of dialysis, kidney transplant, or dialysis until a kidney is available for transplant.