Lasix® is a diuretic that can relieve high blood pressure, fluid retention, and swelling in the extremities. It is commonly prescribed for patients who suffer from chronic liver or kidney diseases and those who are at risk of congestive heart failure. Lasix® works by blocking the absorption of salt and other minerals into the bloodstream, thereby increasing urine production and flushing out the kidneys and urinary tract. As a result, fluid retention is resolved and blood pressure is stabilized. When the proper precautions are taken to prevent dehydration and other negative side effects, Lasix® is generally a very effective means of combating short-term symptoms.
Furosemide, the main ingredient in Lasix®, is absorbed by the gastrointestinal tract and transported through the blood to the kidneys. A structure in the kidney called the loop of Henle contains proteins that trigger sodium and chloride absorption. Furosemide binds to the proteins and inhibits their activity. Excess salt that cannot be absorbed is then processed as waste and expelled through the urine.
When taking Lasix®, fluid retention and the resulting swelling quickly subside as more and more urine is produced and expelled. Blood pressure is lowered as well because the levels of salt and minerals being pumped through the body are decreased. The diuretic takes effect within the first hour and continues to work for about eight hours.
Hospitalized patients with serious heart, liver, and kidney problems are given relatively large single doses of Lasix®. Most adults are given between 20 and 80 milligram initial doses in liquid, tablet, or intravenous form. Pediatric patients require smaller doses, usually about two milligrams per kilogram of body weight. If edema and blood pressure are not relieved within six hours, another equal dose may be given. Patients with chronic but stable disorders may be written prescriptions to take Lasix® at home, usually in smaller doses than are administered in hospitals.
The most common side effect when taking a diuretic is dehydration. As the kidneys are flushed of salt, some important nutrients and fluids are lost as well. Patients need to drink plenty of water or receive intravenous fluids following a dose of Lasix® to avoid complications. Other side effects may include stomach pain, nausea, dizziness, and diarrhea. Some people also develop a slight ringing sound in their ears and light sensitivity. Allergic reactions to furosemide are very rare, but they may cause skin hives and potentially serious airway constriction.