Cirrhosis, the third-leading cause of death in the United States, describes a chronic liver disease characterized by the buildup of scar tissue, according to the Merck Manual. Cirrhosis develops over several years and often doesn't produce symptoms until complications arise. Because cirrhosis cannot be cured, treatment aims to slow the progression of the disease and relieve the symptoms caused by complications. Diuretics, commonly called water pills, eliminate excess fluid, making them useful for treating several complications of cirrhosis.
Portal Hypertension
Blood flows from the stomach and intestines into the liver allowing the liver to hold approximately 13 percent of the total volume of blood at any one time, according to the Lucile Packard Children's Hospital at Stanford. When scar tissue builds up in the liver, blood cannot flow freely. This causes pressure to increase in the portal vein, which is the conduit that carries the blood from the digestive tract to the liver. This condition, known as portal hypertension, redirects blood into the smaller blood vessels surrounding the liver, leading to a buildup of fluid in the body.
Buildup of Ascites
Ascites describes the accumulation of fluid within the abdominal cavity. As blood pressure in and around the liver rises, the body releases vasodilators, which are substances such as vasopressin to help relax blood vessels. Although relaxing the blood vessels helps to reduce the portal hypertension, the vasopressin, an antidiuretic, causes the body to retain more sodium and water. The additional water increases the volume of blood that actually contributes to the high portal blood pressure. The pressure causes the fluid to leak from the blood vessels and accumulate in the abdominal cavity.
Development of Edema
The high blood pressure around the liver affects the flow of blood throughout the body. The portal hypertension can cause the small capillaries in the legs to leak fluid. As the capillaries leak fluid, the body compensates by retaining even more salt and water in order to keep the volume of blood constant. This actually causes capillaries to leak more, allowing fluid to build up in the surrounding tissues, according to MayoClinic.com. The accumulation of fluid causes swelling in the tissues, a condition known as edema.
Function of Diuretics
The kidneys, filled with millions of tiny capillaries, filter blood to remove wastes while also keeping the level of water and salts in balance. Although kidneys remove salt, mainly sodium, the body reabsorbs much of it as the fluids pass through the maze of tubes in the kidneys. Diuretics inhibit the reabsorption of sodium and each molecule of sodium removed from the blood pulls a molecule of water, according to Cardiovascular Pharmacology Concepts. By removing excess water from the body, diuretics help to relieve both ascites and edema.
Effective Diuretics for Cirrhosis
Many types of diuretics exist, each inhibiting the reabsorption of sodium in different places along the tubes within the kidneys. Doctors often choose spirolactone, classified as a potassium sparing diuretic, to treat the complications of cirrhosis, according to information published by Moore and Aithal in Gut Journal. Frusemide, a loop diuretic, can help increase the effectiveness of spirolactone but produces few results in cirrhosis when used alone. Following a diet low in sodium increases the effectiveness of diuretics in treating cirrhosis.
