Why is Lasix prescribed?
Lasix is used in the treatment of high blood pressure and other conditions that require the elimination of excess fluid (water) from the body. These conditions include congestive heart failure, cirrhosis of the liver, and kidney disease. When used to treat high blood pressure, Lasix is effective alone or in combination with other high blood pressure medications. Diuretics help your body produce and eliminate more urine, which helps lower blood pressure. Lasix is classified as a "loop diuretic" because of its point of action in the kidneys.
Lasix is also used with other drugs in people with fluid accumulation in the lungs.
Most important fact about Lasix
Lasix acts quickly, usually within 1 hour. However, since blood pressure declines gradually, it may be several weeks before you get the full benefit of Lasix; and you must continue taking it even if you are feeling well. Lasix does not cure high blood pressure; it merely keeps it under control.
How should you take Lasix?
Take Lasix exactly as prescribed by your doctor.
--If you miss a dose...
Take the forgotten dose as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Never take 2 doses at the same time.
--Storage instructions...
Keep Lasix in the container it came in, tightly closed, and away from direct light. Store at room temperature.
What side effects may occur?
Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Lasix.
• Side effects may include:
Anemia, blood disorders, blurred vision, constipation, cramping, diarrhea, dizziness, dizziness upon standing, fever, headache, hearing loss, high blood sugar, hives, itching, loss of appetite, low potassium (leading to symptoms like dry mouth, excessive thirst, weak or irregular heartbeat, muscle pain or cramps), muscle spasms, nausea, rash, reddish or purplish spots on the skin, restlessness, ringing in the ears, sensitivity to light, skin eruptions, skin inflammation and flaking, stomach or mouth irritation, tingling or pins and needles, vertigo, vision changes, vomiting, weakness, yellow eyes and skin
Why should Lasix not be prescribed?
If you are sensitive to or have ever had an allergic reaction to Lasix or diuretics, or if you are unable to urinate, you should not take Lasix.
Special warnings about Lasix
Lasix can cause your body to lose too much potassium. Signs of an excessively low potassium level include muscle weakness and rapid or irregular heartbeat. To improve your potassium level, your doctor may prescribe a potassium supplement or recommend potassium-rich foods, such as bananas, raisins, and orange juice.
Make sure the doctor knows if you have kidney disease, liver disease, diabetes, gout, or the connective tissue disease, lupus erythematosus. Lasix should be used with caution.
If you are allergic to sulfa drugs, you may also be allergic to Lasix.
If you have high blood pressure, avoid over-the-counter medications that may increase blood pressure, including cold remedies and appetite suppressants.
Your skin may be more sensitive to the effects of sunlight.
Possible food and drug interactions when taking Lasix
If Lasix is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to consult with your doctor before taking Lasix with any of the following:

Aminoglycoside antibiotics such as Garamycin
Aspirin and other salicylates
Ethacrynic acid (Edecrin)
Indomethacin (Indocin)
Lithium (Lithonate)
Norepinephrine (Levophed)
Other high blood pressure medications such as Hytrin and Cardura
Sucralfate (Carafate)
Special information if you are pregnant or breastfeeding
The effects of Lasix during pregnancy have not been adequately studied. If you are pregnant or plan to become pregnant, inform your doctor immediately. Lasix appears in breast milk and could affect a nursing infant. If Lasix is essential to your health, your doctor may advise you to discontinue breastfeeding until your treatment is finished.
Recommended dosage
Your doctor will adjust the dosages of this strong diuretic to meet your specific needs.
ADULTS
Fluid Retention
You will probably be started at a single dose of 20 to 80 milligrams. If needed, the same dose can be repeated 6 to 8 hours later, or the dose may be increased. Your doctor may raise the dosage by 20 milligrams or 40 milligrams with each successive administration--each 6 to 8 hours after the previous dose--until the desired effect is achieved. This dosage is then taken once or twice daily thereafter. Your doctor should monitor you carefully using laboratory tests. The maximum daily dose is 600 milligrams.
High Blood Pressure
The usual starting dose is 80 milligrams per day divided into 2 doses. Your doctor will adjust the dosages and may add other high blood pressure medications if Lasix is not enough.
CHILDREN
The usual initial dose is 2 milligrams per 2.2 pounds of body weight given in a single oral dose. The doctor may increase subsequent doses by 1 to 2 milligrams per 2.2 pounds. Doses are spaced 6 to 8 hours apart. A child's dosage will be adjusted to the lowest needed to achieve maximum effect, and should not exceed 6 milligrams per 2.2 pounds.
Overdosage
Any medication taken in excess can have serious consequences. An overdose of Lasix can cause symptoms of severe dehydration. If you suspect an overdose, seek medical attention immediately.
• Symptoms of Lasix overdose may include:
Dry mouth, excessive thirst, low blood pressure, muscle pain or cramps, nausea and vomiting, weak or irregular heartbeat, weakness or drowsiness.